ICSE Solutions for Class 10 Chemistry – Study of Compounds: Hydrogen Chloride

ICSE Solutions for Class 10 Chemistry – Study of Compounds: Hydrogen Chloride

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APlusTopper.com provides ICSE Solutions for Class 10 Chemistry Chapter 8 Study of Compounds: Hydrogen Chloride for ICSE Board Examinations. We provide step by step Solutions for ICSE Chemistry Class 10 Solutions Pdf. You can download the Class 10 Chemistry ICSE Textbook Solutions with Free PDF download option.

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Short Questions

Question 1: (i) State one condition under which chlorine and hydrogen react to form hydrogen chloride gas.
(ii) Give balanced chemical equation for the above reaction.
(iii) Name the gas which is a covalent compound but becomes electrovalent when dissolved in water ?
(iv) For which gas, ammonia fountain experiment can be used ?
Answer: (i) Presence of diffused sunlight.
(ii) H2 + Cl2  ⟶  2HCl
(iii) Hydrogen chloride (HCl) gas.
(iv) Hydrogen chloride gas.

Question 2: A colourless gas G fumes strongly in the air. The gas gives dense white fumes when a glass rod dipped in ammonia solution is held near the gas.
Answer the following questions:
(i) Name the gas G.
(ii) Name two chemicals used in the preparation of the gas G.
(iii) Write the chemical equations for the reaction of the chemicals named in (ii) when :
(a) The reaction mixture is not heated.
(b) The reaction mixture is heated above 100°C.
(iv) Why does the gas G fume strongly in air ?
(v) Why does the gas G form dense white fumes with ammonium hydroxide ?
Answer: (i) The gas G is hydrogen chlorine gas.
(ii) The chemicals are (i) sodium chloride, (ii) concentrate sulphuric acid.
(iii) (a) NaCl + H2SO4 (conc.)  ⟶  NaHSO4 + HCl (g)
(b) Nacl + NaHSO4  ⟶  Na2SO4 + HCl (g)
(iv) It is because the HCl gas is extremely soluble in water. Thus the gas dissolves in water vapour present in the air to form tiny droplets of hydrochloric acid, which appear in the form of fumes.
(v) The HCl gas reacts with vapours of ammonium hydroxide to form very fine solid particles of ammonium hydroxide which are white in colour. These white particles of solid ammonium hydroxide appear in the form of white fumes.

Question 3: (i) How will you dry HCl acid gas.
(ii) Give three tests of hydrogen chloride.
(iii) Which two colourless gases combine to form a white solid.
Answer: (i) HCl gas can be dried by passing it over conc. H2SO4, which acts as a powerful dehydrating agent.
(ii) Tests for Hydrogen Chloride.
(1) It gives dense white fumes with a rod dipped in NH4OH solution.
(2) It produces white ppt. with AgNO3 solution.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 1
(3) It turns moist blue litmus red.
(iii) NH3 and HCl gases combine to form a white solid NH4Cl
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 2

https://www.youtube.com/watch?v=HUMYd1zQELk

Question 4: (i) (a) What must be added to sodium chloride to obtain hydrogen chloride ?
(b) Write the equation for the reaction which takes place in (a) (i) above.
(c) What would you see when hydrogen chloride is mixed with ammonia ?
(ii) Hydrogen chloride dissolve in water forming an acidic solution:
(a) Name the experiment which demonstrates that hydrogen chloride is very soluble in water.
(b) Give three distinct tests (apart from using an indicator) you would carry out with this solution to illustrate the typical properties of an acid.
Answer: (i) (a) Concentrated Sulphuric acid.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 3
(c) When aqueous solution of ammonia is taken in the jar of hydrogen chloride, it forms dense white fumes of ammonium chloride.
NH+ HCl  ⟶  NH3Cl
(ii) (a) Fountain experiment.
(b) An acid reacts with:
(I) Metal carbonates and bicarbonates with effervescence to liberate CO2.
(II) Acids react with metal sulphides to liberate H2S gas which has smell of rotten eggs
(III) Acids react with metal sulphites to liberate SO2 gas.

Question 5: (i) (a) Name the oxidising agent in the reaction between Manganese dioxide and cone, hydro-chloric acid.
(b) State your observation when a rod dipped in ammonium hydroxide solution is brought near a gas jar containing hydrogen chloride gas.
Manganese (IV) oxide, lead (IV) oxide and red lead (Pb3O4) react with concentrated hydrochloric acid liberating chlorine.
(ii) (a) What is the common property being shown by these metal oxides ?
(b) Write the equation for the reaction of concentrated hydrochloric add with Pb3O4.
(c) What kind of compound can be added to bleaching powder to obtain chlorine ?
Answer: (i) (a) Manganese dioxide acts as an oxidising agent.
(b) Dense white fumes appear in the jar on account of formation of fine particles of ammonium chloride which get suspended in the gas.
(ii) (a) Oxidizing agents
(b) Pb3O4 + 8HCl  ⟶  3PbCl2 + 4H2O + Cl2
(c) Dilute acid (Hydrochloric acid)

Question 6: Answer the following questions, stating your answer only to compounds in the following list: Silver nitrate, hydrochloric acid, chlorine, ammonia, bleaching powder.
(i) What is water sterilizer ?
(ii) Which compound forms curdy white precipitate with hydrogen chloride ?
(iii) Name the gas which produces dense white fumes with ammonia, write the balanced chemical equation.
Answer: (i) Chlorine is water sterilizer.
(ii) Silver nitrate and hydrochloric acid forms white ppt.
AgNO3 + HCl  ⟶  AgCl (White ppt.) + HNO3
White ppt.
(iii) Hydrogen chloride (HCl)
NH3 + HCl  ⟶  NH4Cl (Dense white fumes)

Question 7: (i) When moist chlorine reacts with hydrogen sulphide, two products are formed :
(a) A gas which fumes in moist air; and
(b) A yellow solid.
Name these products.
(ii) What type of reaction is taking place when chlorine acts as a bleaching agent ?
Answer: (i) (a) Hydrogen chloride gas (b) Sulphur
(ii) Oxidation reaction.

Question 8: From the gases-ammonia, hydrogen chloride, hydrogen sulphide, sulphur dioxide-Select the following:
(i) The gas which gives a white percipitate when reacted with silver nitrate solution
acidified with dilute nitric acid.
(ii) A solution of hydrogen chloride in water is prepared. The following substances are added to separate portions of the solution.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 4
Complete the table by writing the gas evolved in each case and its odour, (i) Hydrogen chloride
Answer: (i) hydrogen chloride
(ii)
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 5

Question 9: What is aqua regia ? How does it help in dissolving Gold or Platinum.
Answer: A mixture of 1 part of cone, nitric acid and 3 parts of cone, hydro chloric acid by weight is called aqua regia.
The cone. HCl and conc. HNO3 reacts to form hascent chlorine which reacts with Gold or Platinum to form their respective soluble chlorides.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 6

Question 10: State three uses of hydrochloric acid.
Answer: (i) It is used in the manufacture of silver chloride, which is used widely in photography.
(ii) It is used in the manufacture of dyes, drugs and paints.
(iii) It is used for cleaning metal surface before painting, electroplating, galvanising, soldering etc.

Figure/Table Based Questions

Question 1: Refer to the flow chart diagram below and give balanced equations with conditions, if any, for the following conversions A to D.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 7
Answer:

ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 8

Question 2: In the laboratory preparation of hydrochloric acid, HCl gas is dissolved in water.
(i) Draw a diagram to show the arrangement used for the absorption of HCl in water.
(ii) Why is such an arrangement necessary ? Give two reasons.
(iii) Write the chemical equations for the laboratory preparation of HCl gas when the reactants are :
(A) below 200°C (B) above 200°C
Answer:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 9

Question 3: The diagram shows an apparatus for the laboratory preparation of hydrogen chloride.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 10
(i) Identify A and B.
(ii) Write the equation for the reaction.
(iii) How would you check whether or not the gas jar is filled with hydrogen chloride ?
(iv) What does the method of collection tell you about the density of hydrogen chloride ?
Answer:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 11
(iii) If a moist blue litmus brought near the mouth of gas jar turns red, the gas jar is filled with HCI.
(iv) Hydrogen chloride is denser than air.

Question 4: Study the figure given below and answer the questions that follow:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 12
(i) Identify the gas Y.
(ii) What property of gas Y does this experiment demonstrate ?
(iii) Name another gas which has the same property and can be demonstrated through this experiment.
Answer: (i) Y is hydrochloride (HCl) gas.
(ii) Gas Y is highly soluble in water.
(iii) Ammonia gas.

Question 5: The given figure shown is for the preparation of an acid.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 13
(i) Name the acid prepared by this method.
(ii) Name the reactants used.
(iii) Why an empty flask is used.
(iv) What is the drying agent used ? Why is this drying agent chosen.
(v) What is the role of inverted funnel in the arrangement ?
Answer: (i) Hydrochloric acid.
(ii) Sodium chloride and cone, sulphuric acid.
(iii) An empty flask is used to prevent back suction. If back susetin occurs, the water will collect in it and will not reach the generating flask.
(iv) The drying agent used is concentrated sulphuric acid. Because it does not react with hydrogen chloride.
(v) The role of inverted funnel in the arrangement is :
(a) Prevents back-suction of water.
(b) Providesa large surface area for absorption of HCl gas.

Question 6: (i) Name the experimental illustrated in the diagram.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 14
(ii) Which property of hydrogen chloride is demonstrated by this experiment.
(iii) State the colour of the water that has entered the round bottomed flask.
Answer: (i) Fountain experiment.
(ii) Hydrogen chloride (HCl) is highly soluble in water.
(iii) The colour of water that has entered the round bottomed flask is red.

Reasoning based Questions

Question 1: Mixture of sodium chloride and concentrated sulphuric acid does not heated above the temperature of 170°C while preparing hydrogen chloride. Why ?
Answer: The mixture of sodium chloride and concentrated sulphuric acid is not heated above 170°C in preparing hydrogen chloride gas because at a higher temperature sodium sulphate is formed which is a hard substance and difficult to remove from the reaction flask.
2NaCl + H2S04 → Na2S04 + 2HCl

Question 2: Hydrogen chloride gas cannot be dried over quick time. Why ?
Answer: Because quick lime is basic in nature and combines with moist hydrogen chloride gas forming calcium chloride.

Question 3: Quick lime and phosphorus pentaoxide cannot be used for drying hydrochloric acid gas. Why?
Answer: Quick linie and phosphorus pentaoxide cannot be used for drying HCl gas, because both reacts with HCl.

Question 4: Hydrogen chloride is not collected over water. Why ?
Answer: Hydrogen chloride is not collected over water because it is highly soluble in water.

Question 5: When the stopper of a bottle full of hydrogen chloride gas is opened there are fumes in the air ?
Answer: This is because hydrogen chloride gas has an affinity for water, hence, when the stopper is opened it immediately reacts with water vapour present in the atmosphere which leads to the formation of fumes.

Question 6: Dilute hydrochloric acid cannot be concentrated by distilling (boiling) the dilute acid. Why ?
Answer: When dilute hydrochloric acid is distilled, a constant boiling mixture containing 20 – 24% of hydrochloric acid distills over unchanged at 760 mm Hg pressure. This constant boiling mixture cannot be separated into its constituents by simply distilling.

Question 7: Anhydrous HCl is a poor conductor while aqueous HCl is an excellent conductor. Why ?
Answer: This is because anhydrous HCl does not contain any free ions. But when HCl is dissolved in water, it dissociates into hydronium ion (H3O+) and chloride ion (Cl). Due to the presence of free ions, aqueous solution of HCl conducts electricity.

Question 8: Sodium is not used to prepare hydrogen from hydrochloric acid (or any other acid). Why ?
Answer: Sodium is not used to prepare hydrogen from acids because sodium metal is highly reactive. So, the reaction with acids is much exothermic and there are more chances of explosion. It is also very dangerous to handle sodium metal.

Question 9: Silver nitrate crystals are dissolved in distilled water and not in tap water in order to prepare a solution of silver nitrate as a laboratory reagent. Why ?
Answer: Tap water always contains some amount of dissolved sodium chloride. Thus when the solution of silver nitrate is prepared in tap water, it reacts to form curdy white precipitate of silver chloride.
AgNO3 + NaCl  →  AgCl + NaNO3
To prevent the above chemical reaction, the solution of silver nitrate is prepared in distilled water.

Question 10: Water for drinking purpose and in swimming pools, is treated with chlorine. Give reason.
Answer: Water for drinking purpose and in swimming pools is treated with chlorine because it sterilises the water. Due to its strong oxidizing action, it destroys bacteria, fungus and other microorganisms.

Question 11: Why is it inadvisable to use bleaching powder as a disinfectant when it is mixed with acids ?
Answer: When an acid is mixed into bleaching powder, chlorine gas is liberated which pollutes the atmosphere and makes it unsafe for breathing.
CaOCl2 +  H2SO4   →   CaSO4 + H2O + Cl2

Chemical Tests

Question:
1. Manganese dioxide and copper (II) oxide.
2. Hydrogen chloride gas and carbon dioxide gas.
3. Give three tests for HCl gas.
Answer: 1. When cone, hydrogen chloride is added to manganese dioxide, greenish yellow gas (Cl2) is liberated.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 15
When cone, hydrogen chloride is added to copper (II) oxide, no. gas is liberated but the solution turns bluish because of the formation of copper chloride.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 16
2. When passed into silver nitrate solution, forms a curdy white precipitate of silver chloride.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 17
When passed into lime water, forms a milky white precipitate of calcium carbonate.
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 18
3.(i) When a glass rod dipped in ammonia, solution is held near the vapours of the acid, it form a dense white fumes of ammonium chloride.
(ii) When hydrochloric acid is treated with silver nitrate solution, it forms curdy white precipitate which is soluble in excess of ammonium hydroxide solution.
(iii) When hydrochloric acid is boiled with manganese dioxide, greenish yellow chlorine gas is evolved.

Balancing/Writing the Chemical Equations

Question 1: Write balanced equations for the reaction of dilute hydrochloric acid with each of the following :

1. Iron 2. Sodium hydrogen carbonate
3. Iron (II) sulphide 4. Sodium sulphite
5. Sodium thiosulphate solution 6. Calcium bicarbonate
7. Calcium carbonate 8. Sodium hydroxide
9. Zinc metal 10. Potassium permanganate
11. Red lead heated 12. Magnesium metal
13. Ammonium hydroxide. 14. Magnesium sulphite.
15. Sodium hydrogen sulphide. 16. Manganese dioxide.

Answer:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 19

Question 2: Write balanced equation for the reaction of hydrochloric acid with each of the following :
1. Marble chips
2. Calcium sulphite
3. Lead nitrate solution.
4. Mangnese oxide.
Answer:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 20

Question 3: Complete and balance the following equations :
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 21
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 22
Answer:
ICSE Solutions for Class 10 Chemistry - Study of Compounds Hydrogen Chloride 23

For More Resources

ICSE Solutions for Class 10 Chemistry – Organic Chemistry

ICSE Solutions for Class 10 Chemistry – Organic Chemistry

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APlusTopper.com provides ICSE Solutions for Class 10 Chemistry Chapter 11 Organic Chemistry for ICSE Board Examinations. We provide step by step Solutions for ICSE Chemistry Class 10 Solutions Pdf. You can download the Class 10 Chemistry ICSE Textbook Solutions with Free PDF download option.

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Short Questions

Question 1: The list of some organic compound is given below:
Ethanol, ethane, methanol, methane, ethyne, and ethene.
From the list above, name a compound :
(i) Formed by the dehydration of ethanol by concentrated sulphuric acid.
(ii) Which will give red precipitate with ammoniacal cuprous chloride solution.
(iii) Which forms methanoic acid on oxidation in the presence of copper at 200°C.
(iv) Which has vapour density 14 and turns alkaline potassium permanganate green.
(v) Which forms chloroform on halogenation in the presence of sunlight.
(vi) Which decolourises bromine solution in carbon tetrachloride.
Answer: (i) Ethene. (ii) Ethyne.
(iii) Methane. (iv) Ethene.
(v) Methane. (vi) Ethene.

Question 2: Name the functional group of each of CH3OH, CH3COOH, CH3CHO.
Answer: Alcoholic – OH group present in CH3OH.
Carboxylic – COOH group present in CH3COOH.
Aldehydic – CHO group present in CH3CHO.

Question 3: The melting point of three members X, Y, and Z of a homologous series of hydrocarbons are -180°C, -140°C and -30°C respectively.
(i) Which one of the three would have the lowest number of carbon atoms in its molecule ? Justify your answer.
(ii) Which one of the three have the maximum number of carbon atoms in its molecule ? Justify your answer.
Answer: (i) The homologue with lower number of C-atoms in its molecule has lower melting point. Therefore, compound X has the lowest number of carbon atoms in its molecule. It is clear from the given values of melting points in which -180°C is lowest.
(ii) The homologue with maximum number of carbon atoms in its molecule has the highest melting point. Therefore, compound Z has the maximum number of carbon atoms in its molecules. It is clear from the given values of melting point in which 30°C is the highest of the three.

https://www.youtube.com/watch?v=YAjpntbbQ2w

Question 4: (i) Alkanes are called saturated hydrocarbons. Give a brief explanation, by taking the example of C2H6.
(ii) ‘Alkenes are unsaturated hydrocarbons’. Illustrate it, by taking the example of ethene (C2H4).
(iii) A comound has number of H atoms just double that of C atoms. What types of hydrocarbon is it ?
Answer: (i) Alkane are called saturated hydrocarbons because tetra-valency of each carbon atom is satisfied by single covalent bond.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 1
(ii) Ethene (C2H4) is an unsaturated hydrocarbon, commonly known as alkene. Ethene molecule contains two carbon atoms bonded by double bond.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 2
(iii) The compound is an unsaturarted hydrocarbon having general formula CnH2n. So, this compound is an alkene.

Question 5: (i) In the general formula CnH2n+2 write the meaning of n and 2n + 2.
(ii) Write the formulae and names of the first four members of the alkane family.
(iii) Write the molecular formula of an alkane, which is composed of 16H atoms.
(iv) In a molecule of saturated hydrocarbon the number of C-atoms is 5, what is the number of H-atoms ?
Answer: (i) The number of alkane family represents the general formula CnH2n+2.
In this formula: n = number of carbon atoms in the same molecule of alkane.
2n + 2 = number of H-atoms in a molecule of alkane.
(ii) CH4 (methane), C2H6 (ethane), C3H8 (propane), C4H10 (butane).
(iii) C7H16 (Heptane). [∵2n + 2 = 16, 2n = 16 – 2, 2n = 14,  n = 14/2 = 7].
(iv) According to general formula C4H2n+2 when n = 5, C5H2 x 5+2 or C5H10+2 or C5H12. Thus, the number of hydrogen atom is 12.

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Question 6: The molecules of alkene family are represented by a general formula CnH2n. Now answer the following:
(i) What do n and 2n signify ?
(ii) What is the lowest value which can be assigned to n ?
(iii) What is the molecular formula of alkene, when n = 4 ?
(iv) What is the structural formula of the first member of the alkene family ?
Answer: (i) n = Number of C- atoms in a molecule of alkene.
2n = Number of H-atoms in a molecule of alkene.
(ii) The lowest value of n is 2.
(iii) Butene (C4H6).
(iv) The first member of alkene family is C2H4. It is called ethene, the structural formula is :
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 3

Question 7: (i) Which compound should be heated with sodalime to obtain ethane gas in the laboratory ?
(ii) Write the equation for the reaction in (i) above.
(iii) Write a balanced equation for the complete combustion of ethane.
(iv) Name a solid which can be used instead of concentrated sulphuric acid to prepare ethylene by the dehydration of ethanol.
(v) Ethylene forms an addition product with chlorine. Name this addition product and write its structural formula.
Answer: (i) Sodium propionate.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 4

Question 8: (i) Write the equation, for the preparation of ethylene from ethyl alcohol.
(ii) Write the general formula of a saturated hydrocarbon and give one example of a saturated hydrocarbon with its structural formula.
(iii) Name a compound, which will give acetylene gas, when treated with water.
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 5
(iii) Calcium carbide.

Question 9: (i) Ethane and chlorine react together to form monochloroethane [ethyl chloride].
(a) Write down the structural formula of ethane.
(b) What type of reaction has taken place between ethane and chlorine ?
(ii) The type of reaction between ethene and chlorine is different from that between.ethane and chlorine.
(a) What is the type of reaction between ethene and chlorine.
(b) What feature of the ethene structure makes such reaction possible ?
(c) Name the product of the reaction between ethene and chlorine.
(iii) Ethane bums completely in air or oxygen to give carbon dioxide and water vapours. With a limited supply of air or oxygen, carbon monoxide is farmed. The same gases are found in automobile exhaust gases. Both gases can be considered as atmospheric pollutants.
(a) Write the equation for the complete combustion of ethane.
(b) What danger is associated with carbon monoxide ? .
(c) What effect is associated with too much carbon dioxide in the atmosphere ?
(d) Burning of acetylene [Ethyne] in oxygen, under appropriate conditions, produces a very hot flame. What is this hot flame used for ?
Answer: (i) (a) The structural formula of ethane is given by
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 6
(b) Substitution reaction takes place in between ethane and chlorine.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 7
(ii) (a) Addition reaction takes place in between ethene and chlorine.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 8
(b) Ethene is an unsaturated hydrocarbon [Alkene], containing double covalent bonds, which respond to the addition reaction.
(c) Ethene combines with chlorine to form 1: 2 dichloroethane [Ethylene dichloride]
(iii) (a) Ethane bums in atmospheric oxygen to form carbon dioxide and steam [water].
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 9
(b) Carbon monoxide is a highly poisonous gas. It readily combines with haemoglobin of blood to form carboxy haemoglobin. Carboxy haemoglobin is a stable compound and is incapable of taking up the oxygen from the inhaled air and as a result, people die due to suffocation.
(c) Greenhouse effect or global warming is associated with too much carbon dioxide in the atmosphere.
(d) This hot flame is used for welding and cutting of steel.

Question 10: Indicate the type of reaction that occurs when :
(i) Ethane reacts with chlorine.
(ii) Ethene reacts with chlorine.
(iii) What type of reaction is common in C2H4 and C2H2 ?
(iv) What is formed when ethene reacts with steam at 300°C in the presence of phosphoric acid as catalyst ?
(v) Name a solid which on reaction with water forms :
(a) methane (b) ethyne (acetylene)
(vi) Give the names of each of the following compounds :
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 10
Answer: (i) Substitution reaction. (ii) Addition reaction.
(iii) Addition reaction. (iv) Ethanol.
(v) (a) Aluminium carbide (b) Calcium carbide.
(vi) (a) Butane (b) Ethylene (Ethene) (c) Acetylene (Ethyne).

Question 11: (i) Experimentally, how can poly chlorination of methane be minimized ?
(ii) What are the conditions required for the addition of hydrogen to ethene ?
(iii) Which catalyst is used for the addition of hydrogen to ethene at room temperature ?
(iv) Write the names of all the possible organic products in the reaction of methane with chlorine.
Answer: (i) If excess of methane over chlorine is used, the chance of chlorine reacting with methane is greatest than with any other of the formed chloromethane.
(ii) Addition of hydrogen to ethene occurs at 300°C in the presence of nickel (Ni) catalyst.
(iii) Palladiurh (Pd) or Platinum (Pt) are used as catalyst at room temperature for the addition of hydrogen.
(iv) The main products is methyl chloride (CH3Cl), (CH2Cl2) dichloro methane; (CHCl3) trichloro methane, (CCl4) and tetra chloromethane.

Question 12: How does ethene gas react with the following :
(i) Hydrogen, (ii) Halogen acid, (iii) Sulphuric acid, (iv) Bromine, (v) Alkaline potassium per manganate, (v) HCl gas.
Answer: (i) When a mixture of ethene and hydrogen are passed over heated catalyst (Ni, Pd or Pt), an addition reaction takes place with the formation of ethane, a saturated hydrocarbon.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 11
(ii) When vapours of ethene and hydrobromic acid are mixed at room temperature, they react to form addition product, bromoethane.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 12
(iii) When ethene is passed through cone, sulphuric acid, an addition reaction takes place at room temperature with the formation of ethyl hydrogen sulphate.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 13
(iv) When bromine is passed through the inert solution of ethene, an addition reaction takes place with the formation of 1, 2, dibromoethane.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 14
(v) Ethene reacts with alkaline potassium permanganate solution to form glycol.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 15
(vi) Ethene reacts with HCl to form ethane glycol monochloride.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 16

Question 13: Illustrate the following :
(i) Thermal cracking (ii) Catalytic cracking
(iii) Substitution reactions.
Answer: (i) Thermal Cracking: Breaking of higher hydrocarbons into smaller hydrocarbons on heating,, in absence of air, is called thermal cracking.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 17
(ii) Catalytic Cracking: The breaking of higher hydrocarbons into smaller hydrocarbons, by heating under pressure, in the presence of suitable catalysts, is called catalytic cracking:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 18
(iii) In the presence of diffused light or ultraviolet rays, an atom of hydrogen from the hydrocarbon is substituted by an atom of halogen (Cl, Br, I). These are called substitution reactions.
e.g. : When ethane reacts with chlorine, all the hydrogen atoms are replaced by chlorine atom and substitution products are obtained.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 19

Question 14: (i) The alkenes having how many carbon atoms are in liquid state at normal temperature ?
(ii) The alkenes having how many carbon atoms are in solid state at normal temperature ?
Answer: (i) The alkenes having six to seventeen carbon atoms are in liquid state at normal temperature.
(ii) The alkenes having eighteen or more carbon atoms are in solid state at normal temperature.

Question 15: (i) What is the type of reaction taking place between ethane and chlorine to form monochlorethane ?
(ii) The reaction between ethene and chlorine forms only one product. Name the type of this reaction.
(iii) (1) Draw the structural formula of ethene.
(2) What is the feature of the ethene structure, which allows ethene to react with chlorine in the way it does ?
Answer: (i) Substitution Reaction.
(ii) Addition Reaction.
(iii) (1)
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 20
(2) Unsaturated hydrocarbon with double bond.

Question 16: Compound A is bubbled through bromine dissolved in carbon tetrachloride and the product is CH2Br-CH2Br.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 21
(i) Draw the structural formula of A.
(ii) What type of reaction has A Undergone ?
(iii) What is your observation ?
(iv) Name (not formula) the compound formed when steam reacts with A in the presence of phosphoric acid.
(v) What is the procedure for converting the product of (b)(iv) back to A ?
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 22
(ii) Addition reaction.
(iii) Bromine solution gets decolourised.
(iv) Ethanol
(v) By heating it (ethanol) with concentrated sulphuric acid at 170°C.

Question 17: (i) Give the names and structural formulae of:
(a) An alkane with a carbon to carbon single bond.
(b) An unsaturated hydrocarbon with a double bond.
(ii) (a) Write the equation, for the laboratory preparation of ethvne (acetylene) from calcium carbide.
(b) What is the special feature of the structure of ethyne ?
(iiii) Name the addition product formed between ethene and water.
Answer: (i)
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 23
(b) Ethyne is highly reactive because of presence of one triple bond between two carbon atoms.
(iii) Ethylene glycol.

Question 18: (i) A compound ‘X’ reacts with compound ‘Y’ in presence of lime to form a ‘Z’. It is insoluble in water.
(a) Name the compound X and Y. (b) Name the gas Z.
(c) Write only balanced chemical equation.
(ii) (a) Name the product of the reaction between ethene and chlorine.
(b) Burning acetylene in oxygen, under appropriate conditions, produces a very hot flame. For what purpose, this hot flame is used ?
Answer: (i) (a) X — Sodium ethanoate.
Y — Sodium hydroxide.
(b) Z — Methane (CH4).
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 24
(ii) (a) Ethene dichloride.
(b) For welding.

Question 19: (i) What word is used to describe these three compounds taken together ?
(ii) What is the special feature of the structure of:
(a) C2H4 (b) C2H2
(iii) What type of reaction is common in both of these compounds ?
(iv) Flow is acetylene filled in commercial gas cylinders ?
Answer: (i) Organic compounds.
(ii) (a) C2H4 contains a double bond between two carbon atoms.
(b) C2H2 contains a triple bond between two carbon atoms.
(iii) Addition reaction.
(iv) The commercial gas cylinders of acetylene contain a solution of acetylene in acetone. The cylinder contains a porous material into which the acetone and acetylene are absorbed. The pressure in a freshly filled cylinder of acetylene is about 15 atmosphere.

Question 20: Acetylene can be converted to benzene by suitable temperature and catalyst.
(i) State the temperature and catalyst.
(ii) What type of reaction has taken place ?
(iii) Write down the equation involved.
Answer: (i) 600° C in presence of copper tube.
(ii) Polymerisation reaction.
(iii)ICSE Solutions for Class 10 Chemistry - Organic Chemistry 25

Question 21: (i) (a) A compound has triple bond in its molecule and has only two carbon atoms with two hydrogen atoms. Name the compound.
(b) What is hydrogenation ?
(c) What is halogenation ?
(d) What ‘substitution reaction’ and ‘substitution product’.
(e) What is ‘pyrolysis’ ? What is the other term signifying the same ?
(ii) State the conditions required for the following reactions to take place :
(a) Catalytic hydrogenation of ethyne.
(b) Preparation of ethyne from ethylene dibromide.
Answer: (i) (a) Acetylene H-C ≡ C-H. Or Acetylene.
(b) Addition of hydrogen to some unsaturated hydrocarbons is called hydrogenation.
(c) Addition of halogens (Cl, Br, I) to some unsaturated hydrocarbons is called halogenation.
(d) A substitution reaction is one in which one atom in a molecule is replaced by another atom (or group of atoms). The product of a substitution reaction is known as a substitution product.
(e) Decomposition of alkanes by heat is called pyrolysis. Another term signifying the same is cracking.
(ii) (a) In presence of catalyst like finely divided nickel, platinum, heating upto 473 K.
(b) Hot and concentrated alcoholic solution of potassium hydroxide.

Question 22: A hydrocarbon decolourises KMnO4 solution but does not form any precipitate with ammoniacal AgNO3. Now answer the following questions :
(i) Is the hydrocarbon saturated or unsaturated ?
(ii) What is the type of bonds between two carbon atoms ?
(iii) Does the hydrocarbon belong to alkane, alkene or alkyne family ?
(iv) What will be the change on adding a few drops of bromine solution in a test tube filled with this hydrocarbon ?
Answer: (i) Unsaturated.
(ii) Double bond between two carbon atoms.
(iii) Alkene family.
(iv) Ethene decolourises the solution of bromine in carbon tetrachloride and dibromo-ethane is formed
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 26

Question 23: State two uses of ethane and methane.
Answer: Uses of ethane:
(i) Liquified ethane is used as a fuel in automobiles.
(ii) It is used in the manufacture of organic compounds such as acetic acid, ethyl alcohol etc.
Uses of Methane:
(i) It is used on industrial scale for the preparation of hydrogen by the process of pyrolysis, (ii) It is used in the manufacture of industrial compounds such as carbon tetrachloride, chloroform, formic acid etc.

Question 24: State two uses of ethylene and acetylene.
Answer: Uses of ethylene :
(i) It is used in the manufacture of polyethylene which is a valuable plastic.
(ii) It is used in the artificial ripening of fruits.
Uses of acetylene:
(i) It is used in oxyacetylene flame which is used for cutting and welding of metals.
(ii) It is used in the manufacture of acetaldehyde, acetic acid etc.

Figure/Table Based Questions

Question 1: Methane is the first member of alkane, when it is treated with excess of chlorine in the presence of diffused sunlight forms carbon tetrachloride. Draw the appropriate structural formula of carbon tetrachloride and state the type of bond present in it.
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 27
Structural formula of CCl4. The type of bond present in CCl4 is covalent bond.

Question 2: The figure given below is showing the laboratory preparation of acetylene gas.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 28
(i) How it is prepared in the laboratory ?
(ii) What is the function of acidified copper sulphate solution ?
(iii) Give a reaction in which acetylene gas is prepared by synthesis reaction.
(iv) What happens when acetylene is heated in a copper tube at 600°C ?
Answer: (i) Laboratory preparation of acetylene gas (ethyne gas) : When calcium carbide is treated with water, it forms calcium hydroxide, with the liberation of acetylene.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 29
(ii) Acidified CuSO4 solution is used to absorb impurities of phosphene hydrogen sulphide, ammonia etc.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 30
(iv) Acetylene will polymerise in the copper tube to form benzene.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 31

Question 3: Copy and complete the following table which relates to three homologous series of Hydro-carbons :
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 32
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 33

Reasoning based Questions

Question 1: Hydrocarbons are excellent fuels. Give reason.
Answer: Hydrocarbons are excellent fuels because they ignite easily at low temperature and liberate large amount of heat without producing harmful products.

Question 2: Why alkanes are so inert ?
Answer: It is because in a molecule, a reactive site has one or more unshared pairs of. electrons and a polar bond or an electron deficient atom. Alkanes have none of these.

Question 3: Why alkanes are insoluble in water ?
Answer: Alkanes are insoluble in water because alkanes are called hydrophobic hydrocarbons. They have phobia for water. These are insoluble because these cannot make hydrogen bonds with water molecules.

Question 4: Methane is called as marsh gas. Why ?
Answer: Because methane is formed by the decomposition of plant and animal matter lying under water in marshy areas.

Question 5: Methane does not undergo addition reactions, but ethene does. Why ?
Answer: Because methane is saturated hydrocarbon while ethene is an unsaturated hydrocarbon. Addition reactions are characteristic properties of unsaturated hydrocarbons.

Question 6: Why it is dangerous to bum methane in an insufficient supply of air ?
Answer: Because it will form carbon monoxide which is poisonous for human beings as it cuts off the oxygen supply by forming carboxy haemoglobin in the blood.

Question 7: Why light or heat is necessary for chlorination of alkanes ?
Answer: The Cl-Cl bond must be broken to form Cl radicals, before the chlorination of alkanes can commence. The breaking of bond requires energy which is supplied either by heat or light.

Question 8: Ethene undergoes addition reactions with halogens whereas ethane undergoes substitution reactions. Why ?
Answer: Ethene is an unsaturated hydrocarbon so, it adds up a molecule of halogen to give a saturated compound, whereas, ethane is a saturated hydrocarbon compound and hence, can only undergo substitution reaction with halogen.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 34

Question 9: Alkynes are unsaturated hydrocarbons. Give reason.
Answer: Alkynes have triple bonds, so they are unsaturated hydrocarbon.

Question 10: Why ethyne is more reactive than ethane ?
Answer: Ethyne is an unsaturated hydrocarbon with a triple covalent bond. Ethane is a saturated hydrocarbon and hence is less reactive than ethyne.

Question 11: Acetylene bums with sooty flame. Why ?
Answer: Acetylene has higher proportion of carbon and all carbon in it does not burn completely. Hence, unburnt carbon particles make the flame sooty.

Question 12: Why pure acetic acid known as glacial acetic acid ?
Answer: Because on cooling below its melting point (17°C) it solidifies and forms little ice-like crystals.

Chemical Tests

Question:
1. Ethene and ethane.
2. Ethyne and ethane.
3. Alkanes, alkenes and alkynes.
Answer:
1. Ethene gas decolourises bromine solution and potassium permanganate solution. But, ethane gas does not change the colour of these solutions.
2. Ethyne gas forms a white precipitate with ammonical solution of silver nitrate and red ppt. with ammonical solution of copper (I) chloride. But, ethane does not respond to such tests.
3.

S.No.

Test Alkanes Alkenes Alkynes

(i)

Bromine Test Add a few drops of sol. of bromine in carbon tetra-chloride to the hydrocarbon. No change takes place. The red colour of bromine is decolorised. The red colour of bromine is decolorised.

(ii)

Alkaline Potassium Permanganate Test: Add a few drops of alkaline pot. permanganate sol. To the hydrocarbon. No change takes place. The purple colour of Potassium permanganate is decolorised.

The purple colour of potassium permanganate is decolorised.

(iii) Ammoniacal Cuprous Chloride Test: Add a few drops of ammoniacal cuprous chloride sol. to thehydrocarbon. No change takes place. No change takes place.

A red ppt. of copper acetylide is formed.

 

Balancing/Writing the Chemical Equations

Question 1:
1. Monochioro ethane is hydrolysed with aqueous KOH.
2. A mixture of sodalime and sodium acetate is heated.
3. Ethanol under high pressure and low temperature is treated with acidified potassium dichromate.
4. Water is added to calcium carbide.
5. Ethanol reacts with sodium at room temperature.
6 Reaction between 4, 2-dibromoethane and alcoholic potassium hydroxide.
7, Preparation of ethane from sodium propionate.
8. Preparation of ethanol from monochioroethane and aq. sodium hydroxide.
9. A saturated hydrocarboñ fròm iodomethane.
10. An unsaturated hydrocarbon from an alcohol.
Il. An unsaturated hydrocarbon from calcium carbide.
12. An alcohol from ethyl bromide.
13. Reaction between ethyl alcohol and acetic acid.
14. Reaction of chlorine with excess of methane.
15. Addition of chlorine to ethene at ordinary temperature.
16. Burning of ethanol in air.
17. Preparation of ethane from Sodium propionate.
18. Preparation of ethene from lodoethane.
19. Preparation of ethyne from Calcium carbide.
20. Preparation of methanol from lodomethane.
21. A mixture of methane and oxygen is heated in the presence of metallic oxide;
22. A mixture of methane and air is heated at 400°C.
23. Excess chlorine react with methane.
24. Excess chlorine react with ethane.
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 35
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 36

Question 2: How will you bring about the following conversion?
1. Methane to methyl chloride. 2. Methane to methyl alcohol.
3. Methane to formaldehyde. 4. Methane to formic acid.
5. Ethane to ethyl chloride. 6. Ethane to ethyl alcohol.
7. Ethane to acetaldehyde. 8. Ethane to acetic acid.
9. Ethane to ethene. 10. Ethyne to ethene.
11. Ethene to ethane. 12. Ethyne to ethane.
13. Methane to formic acid. 14. Ethane to Acetic acid.
15. Ethane to hexachioroethane
Answer:
1. When a mixture of methane and chlorine in the ratio of 1 : 1 by volume is exposed to diffused sunlight, methyl chloride is formed.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 37
2. Methane, is first converted into methyl chloride by chlorination, in the presence of diffused sunlight. Methyl chloride on hydrolysis forms methyl alcohol.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 38
3. Methyl alcohol obtained from above is subjected to oxidation with sodium dichromate and dilute sulphuric acid to form formaldehyde.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 39
4. Formaldehyde obtained from above, when subjected to oxidation with sodium dichromate and dilute sulphuric acid, forms formic acid.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 40
4. When equal volumes of ethane and chlorine are exposed to diffused sunlight, they react to form ethyl chloride (monochloro ethane).
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 41
5. When equal volumes of ethane and chlorine are exposed to diffused sunlight, they form ethyl chloride, which when treated with aqueous solution of potassium hydroxide (KOH), undergoes hydrolysis to form ethyl alcohol.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 42
6. Ethane is first converted to ethyl chloride by chlorination. Ethyl chloride undergoes hydrolysis, when treated with aqueous solution of potassium hydroxide, resulting in the formation of ethyl alcohol. Ethyl alcohol undergoes oxidation in the presence of sodium dichromate, acidified with dilute sulphuric acid, which provides nascent oxygen and oxidise ethyl alcohol to acetaldehyde (ethanol).
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 43
7. Acetaldehyde,when-subjected to oxidation with sodium or potassium dichromate and dilute sulphuric Acid, gets oxidized to form acetic acid.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 44
8. Ethane on chlorination forms ethyl chloride which when treated with alcoholic KOH, undergoes, dehydro chlorination to form ethene.
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 45
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 46

IUPAC Naming/ Writing the Structural Formula

Question 1:
Give the structural formula of the following :

1. Ethanol. 2. 1-propanal
3. Ethanoic acid 4. 1, 2, dichloroethane
5. An isomer of n-butane 6. 2-propanol
7. Diethyl ether 8. Methanoic acid
9. Ethanal 10. Ethyne
11. Acetone 12. 2-methyl propane
13. Ethanoic acid 14. But-2-yne
15. Two isomers of Butane 16. Ethane
17. Vinegar 18. Marsh gas
19. An alcohol 20. 2-Butyne

Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 47
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 48
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 49

Question 2: Give the correct IUPAC name structural formulae given below:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 50
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 51
Answer:

1. Propanal  2. Propan-1-ol
3. Propyne  4. Pentan-3-ol
5. 2-methyl propane,  6. Ethanoic acid
7. 1, 2-dichloroethane  8. 2-Chloro hex-5-yn-1-al
9. 3-methyl-but-3-en-1-ol  10. 1-chloro-2methyl propane
11. 2,4-dimethyl-pentan-3-one  12. 2-methoxy-4-pentan-3-one
13. 2-chloro-3-hydroxy propanal  14. Ethanedioic acid
15. Pent-1-en-4-yne  16. Pent-3-en-1-yne
17. Propane-1-ol  18. Pentan-2-one
19. 2-Methyl Pentanoic acid  20. Hexan-3-one
21. 2-Bromo, 2-methyl butanol  22. But-2-yne
23. 1,2,-dichloro ethane .  24. 2-methyl butane
25. 2-methyl propane

Question 3: Give the formula of the next highest homologue of:
1. Methanol 2. Ethane
3. Ethene 4. Ethyne
5. Propyl 6. Methanoic acid
Answer:
ICSE Solutions for Class 10 Chemistry - Organic Chemistry 52

For More Resources

ICSE Solutions for Class 10 Chemistry – Sulphuric Acid

ICSE Solutions for Class 10 Chemistry – Sulphuric Acid

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APlusTopper.com provides ICSE Solutions for Class 10 Chemistry Chapter 10 Sulphuric Acid for ICSE Board Examinations. We provide step by step Solutions for ICSE Chemistry Class 10 Solutions Pdf. You can download the Class 10 Chemistry ICSE Textbook Solutions with Free PDF download option.

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Short Questions

Question 1: Sulphuric acid is said to be dibasic acid. What is meant by the term “dibasic” ?
Answer: Basicity of an acid is the number of H+ ions that one formula unit of an acid liberates, e.g.,
Monobasic = HCl, HNO3, etc.
Dibasic = H2SO4, H2SO3 etc.
Each acid can form as many kinds of salts, as it has hydrogen ions. Sulphuric acid can form two kinds of salts, i.e., SO42- and HSO4. It ionizes in water to form two hydrogen ions. Hence, it is said to be dibasic.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 1
These acids can yield two kinds of salts, i.e., the normal salt and the acid salt.

Question 2: Some bacteria obtain their energy by oxidizing sulphur, producing sulphuric acid as a by-product. In the laboratory, or industrially, the first step in the conversion of sulphur to sulphuric acid is to produce sulphur dioxide. Then sulphur dioxide is converted to sulphur trioxide which reacts with water, producing sulphuric acid.
(i) Name one catalyst used industrially which speeds up the conversion of sulphur dioxide to sulphur trioxide.
(ii) Write the equation for the conversion of sulphur dioxide to sulphur trioxide. Why does this reaction supply energy ?
(iii) What is the name of the compound formed between sulphur trioxide and sulphuric acid.
Answer: (ii) Platinum and Vanadium pentaoxide.
(i) When conversion of SO2 to SO3 takes place according to the following reaction.
SO2 + O2  ⟶  2SO3 + 45 kcal.
The 45 kcal energy supplied by above reaction.
(iii) Oleum (H2S2O7).

Question 3: (i) Write balanced equations for the three chemical reactions that take place during the conversion of sulphur dioxide to sulphuric acid in the contact process.
(ii) Name the catalyst used in the contact process.
(iii) Name another ore which on roasting gives sulphur dioxide.
Answer:
(i) The chemical reactions are summarised as below:
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 2
(ii) Platinized asbestos or V2O5
(c) Zinc blende or ZnS
2ZnS + 3O2  ⟶  2ZnO + 2SO2

Question 4: (i) With the help of equations, give an outline for the manufacture of sulphuric acid by the contact process.
(ii) What property of sulphuric acid is shown by the reaction of concentrated sulphuric acid when heated with (a) potassium nitrate (b) carbon ?
Answer: (i)
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 3
(ii) (a) Non-volatile nature. (b) Oxidising property.

Question 5: (i) Which two gases are combined during contact process ?
(ii) Write the equation for the reaction between zinc and the final product of the contact process ?
(iii) What happens when sulphur trioxide gas is passed into concentrated sulphuric acid.
Answer: (i) SO2 and O2 (sulphur dioxide and oxygen)
(ii) Zn + 2H2SO4 (Conc.)  ⟶  ZnSO4 + 2H2O + SO2
(iii) Sulphur trioxide gas dissolves in concentrated sulphuric acid to form fuming sulphuric acid, commonly known as oleum.
SO3 + H2SO4  ⟶  H2S2O7 (Oleum)

Question 6: While diluting concentrated sulphuric acid, the acid should be added to water and not water to the acid. Explain ?
Answer: When equal volumes of the acid and water are mixed at room temperature, the temperature may reach up to 120°C. Therefore, dilution of the acid should be done by adding small quantity of acid into water.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 4
If water is added to concentrated sulphuric acid, the molecules of the acid try to grasp the molecules of water resulting in molecular tension, liberating heat and due to sudden rise in temperature, the acid starts splashing.
If a drop of concentrated acid is added to water, the molecules of acid go in different directions to pick up water which is available in plenty. Although the same amount of heat is formed but since the molecules are spread out, no splashing occurs.

Question 7: (i) Which property of sulphuric acid is used to prepare the hydrochloric and nitric acid respectively.
(ii) What is the catalyst used in catalytic chamber and what is the temperature used ?
Answer: (i) Non-volatile nature of sulphuric acid is responsible to prepare HCl and HNO3 by using H2SO4.
(ii) The catalyst used is platinized asbestos or vanadium pentaoxide and the temperature used is about 450°C.

Question 8: (i) (a) Name the acid formed when sulphur dioxide dissolves in water.
(b) What are the two necessary conditions for the direct combination of sulphur dioxide and chlorine forming sulphuryl chloride ?
(c) State the property of sulphur dioxide which causes potassium permanganate to change its colour from purple to colourless.
(ii) Answer the following questions related to dilute and concentrated sulphuric acid.
(a) Which acid does not react with metals that are placed below hydrogen in activity series ?
(b) Which acid will give white precipitates with barium sulphate.
Answer: (i) (a) Sulphurous acid
(b) Sunlight and absence of moisture
(c) Reducing.
(ii) (a) Dilute sulphuric acid.
(b) Dilutesiilphuric acid.

Question 9: Give one reaction in each case to illustrate the following properties of sulphuric acid:
(i) As an acid. (ii) As an oxidising agent.
(iii) As a dehydrating agent. (iv) As a less volatile acid.
Answer: (i) Dilute sulphuric acid reacts with metals above hydrogen in the activity series, for example, magnesium to liberate hydrogen gas and magnesium sulphate.
Mg + H2SO4  ⟶  MgSO4 + H2
(ii) When sulphur is heated with concentrated sulphuric acid, it is oxidised to sulphur dioxide.
S + 2H2SO4  ⟶  3SO2 (Sulphur dioxide) + 2H2O
(iii) Add few drops of concentrated sulphuric acid to blue coloured crystals of copper (II) sulphate. After sometime, white anhydrous copper (II) sulphate is left, due to loss of water of crystallization.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 5
(iv) Concentrated sulphuric acid, when heated with sodium chloride, produces volatile hydrochloric acid.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 6

Question 10: What happens when cone, sulphuric acid reacts with:
(i) Potassium chloride
(ii) Zinc nitrate.
Answer: (i) Cone, sulphuric acid reacts with potassium chloride and forms hydrogen chloride and potassium hydrogen sulphate.
KCl + H2SO4  ⟶  KHSO4 + HCl
(ii) Cone, sulphuric acid reacts with zinc nitrate to form zinc sulphate and nitric add.
Zn(NO3)2 + H2SO4  ⟶  ZnSO4 + 2HNO3

Question 11: State how you can obtain:
(i) Sulphur dioxide from sulphur.
(ii) Hydrogen sulphide from iron (II) sulphide.
(iii) Oxalic add.
(iv) Sodium hydroxide
(v) Hydrogen sulphide gas
Answer: (i) When sulphur is bumtin a deflagerating spoon, it melts to form a reddish brown liquid which catches fire. It burns with a blue flame forming an extremely pungent gas sulphur dioxide.
S + O2  ⟶  SO2
(ii) In the laboratory, hydrogen sulphide gas is prepared by the action of dilute sulphuric acid on ferrous sulphide.
FeS + H2SO4  ⟶   FeSO4 + H2S
(iii) Concentrated sulphuric acid, when heated with oxalic acid crystals, it absorbs water from oxalic acid and-mixtures of carbon monoxide and carbon dioxide is formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 7
In this reaction sulphuric acid acts as a dehydrating agent.
(iv) Sodium hydroxide solution reacts with dilute sulphuric acid to form sodium sulphate and water.
2NaOH + H2SO4  ⟶  Na2SO4 + 2H2O
In this reaction sulphuric acid acts as an acid as it neutralizes sodium hydroxide to form salt and water only.
(v) When hydrogen sulphide gas is passed through concentrated sulphuric acid, it is oxidized to free sulphur. Sulphur dioxide and water are also formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 8
In this reaction sulphuric acid acts as an oxidizing agent.

Question 12: Which property of sulphuric acid is used in the following:
(i) As a source of hydrogen when treated in dilute form with metals like Zn, Mg, Fe, etc.
(ii) Production of hydrogen chloride on treating concentrated add with sodium chloride.
(iii) Production of sulphur dioxide on heating in concentrated form with copper turnings.
(iv) Liberation of sulphur from H2S with concentrated form.
(v) Charring of sugar with hot concentrated add.
(vi) Liberation of ethylene gas with hot concentrated add.
(vii) Liberation of carbon monoxide with hot concentrated add.
Answer: (i) Addic property. (ii) Non volatile nature.
(iii) Oxidising nature. (iv) Oxidising property.
(v) Dehydrating nature. (vi) Dehydrating nature.
(vii) Dehydrating nature.

Question 13: Some properties of Sulphuric add are listed below. Choose the property A, B, C or D which is responsible for the reactions (i) to (v). Some properties may be repeated:
A. Acid
B. Dehydrating agent
C. Non-volatile acid
D. Oxidizing agent
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 9
Answer: (i) B, (ii) D (iii) C, (iv) A (v) A (vi) B, (vii) C, (viii) A, (ix) D.

Question 14: A, B, C and D summarize the properties of Sulphuric acid depending on whether it is dilute or concentrated. Choose the property (A, B, C or D), depending on which is relevant to each of the preparations (i) to (iii):
A. Dilute acid (typical acid properties)
B. Non-volatile acid.
C. Oxidizing agent.
D. Dehydrating agent
(i) Preparation of Hydrogen Chloride.
(ii) Preparation of Ethene from Ethanol.
(iii) Preparation of Copper sulphate from Copper oxide.
Answer: (i) B (non-volatile acid).
(ii) D (dehydrating agent)
(iii) A (dilute acid).

Question 15: Name from the list of substances given below, the substances which you would use to prepare each of the following salts, named in parts (i) to (iv):
The substances are:
Copper, Lead, Sodium, Zinc, Copper oxide, Lead carbonate, Sodium Carbonate solution, Dilute hydrochloric acid, Dilute nitric acid and Dilute sulphuric acid:
(i) Zinc sulphate; (ii) Copper sulphate; (iii) Sodium sulphate; (iv) Lead sulphate.
Answer: (a) For zinc sulphate — Zinc and dilute sulphuric acid.
(b) For copper sulphate — Copper oxide and dilute sulphuric acid.
(c) For sodium sulphate — Sodium carbonate and dilute sulphuric acid.
(d) For lead sulphate — Lead carbonate + dil. nitric and then dil. sulphuric acid.

Question 16: Give examples of the use of sulphuric acid as:
(i) An electrolyte in everyday use. (ii) A non-volatile acid.
(iii) An oxidizing agent.
Answer: (i) In lead accumulators or in storage batteries.
(ii) In the manufacture of other acids like nitric acid, hydrochloric acid and phosphoric acid.
(iii) For cleaning metals before enameling, electroplating and galvanizing, as a pickling agent.

Question 17: Some of the properties of six pure substances represented by A, B, C, D, E and F are given below:
A-when heated with concentrated sulphuric acid, it gives off a choking gas which dissolves in water giving an acid.
B- is a greenish-yellow gas which dissolves in water and when this aqueous : solution is exposed to sunlight, bubbles of a gas are evolved, which rekindles a glowing splinter.
C- is a metal which when treated with concentrated nitric acid, gives off a brown gas and a blue solution is obtained.
D- is a white solid, which when heated, gives off a sweet smelling gas which rekindles a glowing splinter.
E- is a heavy oily liquid which when added to moist sugar, chars it into a black porous mass.
F- is a gas which turns moist red litmus to blue. When the gas is passed over heated copper oxide, an inactive gas is obtained.
(i) Name the substances A, B, C, D, E and F.
(ii) Write equations for the following reactions involving A, B, C, D, E and F.
(a) A is heated with concentrated sulphuric acid.
(b) An aqueous solution of B is exposed to bright sunlight.
(c) Concentrated nitric acid and the metal C are heated.
(d) The action of heat on D.
(e) Oily liquid E is added to sugar.
(f) The action of F on heated copper (II) oxide.
Answer: (i) A is sodium chloride, B is chlorine gas, C is copper, D is ammonium nitrate, E is concentrated sulphuric acid and F is ammonia gas respectively.
(ii) When sodium chloride is heated with concentrated sulphuric acid, hydrogen chloride gas is liberated and sodium sulphate is also formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 10
(a) Chlorine gas reacts with water in the presence of sunlight to liberate oxygen gas and hydrochloric acid is formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 11
(b) Copper and concentrated nitric acid when heated, a brown gas, nitrogen dioxide is evolved and-a blue coloured copper nitrate is formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 12
(c) Ammonium nitrate on heating gives off a sweet smelling gas nitrous oxide, commonly known as laughing gas and water is formed.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 12a
(d) Sulphuric acid acts as dehydrating agent and chars the sugar to black porous mass, i.e., carbon.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 13
(e) When ammonia is passed over heated copper (II) oxide, it is oxidized to form nitrogen and water. Copper (II) oxide itself reduces to metallic copper.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 14

Figure/Table Based Questions

Question 1: (i) Copy and complete the following table: Column 3 has the names of gases to be prepared using the substance you enter in column 1 along with dilute or concentrated sulphuric acid as indicated by you in column 2.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 15
(ii) Write the equations for the laboratory preparation of:
(a) Sodium sulphate using dilute sulphuric acid.
(b) Lead sulphate using dilute sulphuric acid.
Answer: (i)
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 16
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 17

Question 2: Study the diagram given below, which illustrates the manufacture of sulphuric acid.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 18
(i) Write the names of the substances A to F.
(ii) Describe how gas C could be identified.
(iii) Explain the purpose of V2O5 or Pt.
(i) A—Sulphur
B—Iron pyrites
C—Sulphur
D—Oxygen
E—Concentrated sulphuric acid
F—Water
(ii) The gas C will turn acidified potassium dichromate paper green.
(iii) V2O5 or Pt acts as a catalyst and increases the rate of formation of sulphur trioxide from sulphur dioxide and oxygen.

Question 3: (i) Name the catalyst which helps in the conversion of sulphur dioxide to sulphur trioxide in step C.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 19
(ii) In the Contact process for the manufacture of sulphuric acid, sulphur trioxide is not converted to sulphuric acid by reacting it with water. Instead a two step procedure is used. Write the equations for the two steps involved in D.
(iii) What type of substance will liberate sulphur dioxide from sodium sulphite in step E ?
(iv) Write the equation for the reaction by which sulphur dioxide is converted to sodium sulphite in step F.
Answer:
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 20

Reasoning based Questions

Question 1: Why concentrated sulphuric acid is called the “oil of vitriol” ?
Answer: Concentrated sulphuric acid is called “Oil of vitriol” because of its oily appearance and the fact that it is present in vitreous or glassy substances like ferrous sulphate, alum, etc.

Question 2: For the production of concentrated sulphuric acid, sulphur trioxide is not directly dissolved in water. Why ?
Answer: Because with water, sulphur trioxide forms a mist of fine drops of sulphuric acid.

Question 3: The impurity of arsenic oxide must be removed before passing the mixture of sulphur dioxide and air through the catalytic chamber in contact process. Why ?
Answer: Because the impunty of arsenic oxide makes the catalyst poisonous.

Question 4: Why concentrated sulphuric acid is kept in air tight bottles ?
Answer: Concentrated sulphuric acid readily absorbs moisture from atmosphere and gets diluted. Hence, it is kept in air tight bottles.

Question 5: Why the level of concentrated sulphuric acid gets higher if it is left in an open vessel for a week ?
Answer: This is due to the hygroscopic nature of sulphuric acid. It absorbs water vapour from the atmosphere.

Question 6: Why sulphuric acid behaves as an acid when diluted with water ?
Answer: When sulphuric acid is diluted with water, it ionizes almost completely into hydrogen ions (H+) and sulphate ions (SO42-)
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 21
Since presence of H+ ions imparts acidic character, therefore solution of sulphuric acid in water behaves as an acid.

Question 7: Why the wooden shelves on which cone, sulphuric acid bottles are kept, stained black ?
Answer: Concentrated sulphuric acid is a very powerful dehydrating agent. It removes atoms of hydrogen and oxygen in the form of water from the cellulose [(C6H12O5)n], leaving behind carbon. It is black carbon which appears in the form of black stains.

Question 8: A black spongy mass is formed, when concentrated sulphuric acid is added to sugar. Why ?
Answer: Sulphuric acid has great affinity for water, hence when concentrated sulphuric acid is added to sugar, it absorbs water from sugar by removing hydrogen and oxygen atoms in the ratio of 2:1 from sugar molecules. The sugar is charred producing black spongy mass of carbon, which is known as sugar charcoal.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 22

Question 9: When blue crystals of copper (II) sulphate are added to concentrated sulphuric acid crystals turn white. Why ?
Answer: Hydrated copper (II) sulphate, when added to concentrated sulphuric acid, loses water of crystallization and thus white anhydrous copper (II) sulphate is formed. The blue coloured hydrated copper (II) sulphate turns white due to the loss of water of crystallization.
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 23a

Question 10: Why brisk effervesence is seen when H2SO4 is added to sodium carbonate ?
Answer: This brisk effervescence is seen due to the evolution iof carbon dioxide gas.

Chemical Tests

Question:
1. Dilute sulphuric acid and dilute hydrochloric acid.
2. Chlorine gas and sulphur dioxide gas
Answer: When barium chloride solution is added to the dilute sulphuric acid, thick white precipitate of barium sulphate is formed which is insoluble in any mineral acid such as nitric acid or hydrochloric acid
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 23b
With dilute hydrochloric acid, no effect is observe.
Chlorine gas turns starch iodide paper blue and sulphur dioxide gas turns moist acidified potassium dichromate paper green.

Balancing/Writing the Chemical Equations

Question 1: Write balanced chemical equation for the following :
1. Action of concentrated sulphuric acid on carbon.
2. Dilute sulphuric add produdng hydrogen.
3. Dilute sulphuric add is poured over sodium sulphite
4. Zinc reacts with cone. Sulphuric add.
5. Sodium bicarbonate and dilute sulphuric acid.
6. Sodium nitrate and cone. Sulphuric add.
7. Iron reads with dil sulphuric acid.
8. Sulphur is heated with concentrated sulphuric add.
9. Concentrated sulphuric acid is poured over sugar.
10. Dilute sulphuric add with Copper carbonate.
11. Dilute sulphuric acid with Lead nitrate solution.
12. Dilute sulphuric acid with Zinc hydroxide.
13. Concentrated sulphuric acid with barium chloride.
14. Concentrated sulphuric add with sulphur trioxide.
15. Sodium sulphite with dilute sulphuric acid.
16. Concentrated sulphuric acid with potassium chloride.
17. Concentrated sulphuric add with zinc nitrate.
18. Concentrated sulphuric add with potassium nitrate.
19. Potassium hydrogen carbonate and sulphuric add.
20. Sodium nitrate and concentrated sulphuric acid.
Answer:
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 24
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 25

Question 2: Complete and balance the following chemical equations :
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 26
Answer:
ICSE Solutions for Class 10 Chemistry - Sulphuric Acid 27

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