ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

Max Marks : 80
[2 Hours]

General Instructions

  • Answers to this Paper must be written on the paper provided separately.
  • You will not be allowed to write during the first 15 minutes.
  • This time is to be spent in reading the Question Paper.
  • The time given at the head of this paper is the time allowed for writing the answers.
  • Section I is compulsory. Attempt any four questions from Section II.
  • The intended marks for questions or parts of questions are given in brackets [ ].

Section-I [40 Marks]
(Attempt all questions from this section)

Question 1.
(a) Fill in the blanks with the correct choice given in brackets. [5]
(i) In an ionic compound, the bond is formed due to of electrons. …………………… [sharing/transfer]
(ii) Zinc is reactive than aluminum …………………… [less/more]
(iii) The chemical reaction in which heat is absorbed is known as reaction ……………………. [endothermic/ exothermic]
(iv) The molecular formula of ammonium sulphate is …………………… [NH4SO4/(NH4)2SO4]
(v) If an element has two electrons in its outermost shell, then it is likely to be …………………… [metallic/ non-metallic]
Answer:
(i) transfer
(ii) less
(iii) endothermic
(iv) (NH4)2SO4
(v) Metallic

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(b) Choose the correct answer from the options given below : [5]
(i) The gas that causes the greenhouse effect:
(A) Oxygen
(B) Ammonia
(C) Methane
(D) Hydrogen Sulphide
Answer:
(C) Methane

(ii) According to the modem periodic law, the properties of elements are a periodic function of their :
(A) Atomic volume
(B) Atomic number
(C) Atomic weight
(D) Mass number
Answer:
(B) Atomic number

(iii) Which of the following has water of crystallization ?
(A) Potassium chloride
(B) Sodium chloride
(C) Sodium nitrate
(D) Washing soda crystals
Answer:
(D) Washing soda crystals

(iv) The gas which has a rotten egg smell is :
(A) Hydrogen sulphide
(B) Ammonia
(C) Sulphur dioxide
(D) Hydrogen chloride
Answer:
(A) Hydrogen sulphide

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(v) The temperature of 0° Celcius on the Kelvin scale is equal to :
(A) – 273 K
(B) 273 K
(C) 0 K
(D) 100 K
Answer:
(B) 273 K

(c) Name the gas evolved in each of the following cases : [5]
(i) Copper carbonate is heated strongly.
(ii) Action of dilute hydrochloric acid on sodium sulphite.
(iii) Nitrogen combines with hydrogen.
(iv) Action of dilute sulphuric acid on sodium carbonate.
(v) Addition of sodium to cold water.
Answer:
(i) Carbon dioxide
(ii) Sulphur dioxide
(iii) Ammonia
(iv) Carbon dioxide
(v) Hydrogen

(d) Give a reason for each of the following : [5]
(i) Noble gases do not combine with other elements to form molecules.
(ii) Dilute nitric acid cannot be used in the preparation of hydrogen.
(iii) Hydrogen although lighter than air, is not collected by the downward displacement of air.
(iv) Anhydrous calcium chloride turris into a colourless solution when exposed to air.
(v) Metals form positive ions.
Answer:
(i) Noble gases have 2 electrons in their outermost shell that is completely filled and moreover, it is the maximum number of valence electrons their outer shell can hold hence, these are unreactive.

(ii) When metal reacts with water it produces hydrogen gas. Nitric acid is a very strong oxidizing agent and it oxidizes the hydrogen gas produced during the reaction of metal with water. Hence, dilute nitric acid cannot be used in the preparation of hydrogen.

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(iii) Hydrogen gets oxidized when it is exposed to oxygen which makes it bum with a pale blue flame and the residue is water. This means that it mixes with oxygen. Downward displacement of air requires a gas that does not mix with air and is lighter than air. Hydrogen is lighter than air but mixes with air.

(iv) Calcium chloride is deliquescent. If exposed to air, it will absorb sufficient water from the air to allow it to dissolve. After a short while, instead of a white lump, a pool of clear liquid is formed.

(v) Ions are formed when an atom either loses or gains electron and gets charged accordingly. All metals have electrons in their outermost shell which can be easily lost.

(e) What do you observe when : [5]
(i) Iodine crystals are heated in a test tube ?
(ii) Iron nails are added to copper sulphate solution ?
(iii) Lead nitrate crystals are heated strongly ?
(iv) Ferric chloride crystals are exposed to atmosphere for some time ?
(v) Blue copper sulphate crystals are heated ?
Answer:
(i) When Iodine crystals are heated in a test tube, the van der Waals forces are easily overcome and the molecule breaks into gas phase. They sublime and form a purple coloured dense vapours.

(ii) When iron nails are added to copper sulphate the blue colour of the solution fades eventually and turns into light green due to the formation of ferrous sulphate.

(iii) When lead nitrate crystals are heated strongly, lead decomposes and leaves yellow fesidue of lead monoxide, brown gas nitrogen dioxide and colourless gas oxygen are evolved.

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(iv) When ferric chloride crystals are heated hydrated hydrogen chloride is formed which is rarely observed in its natural form.

(v) The blue coloured copper sulphate crystals turn white due to the loss of water molecules. The formula of copper sulphate is CuSO4.5H2O. When copper sulphate is heated, it loses water molecules and hence it loses blue colour.

(f) (i) State Boyle’s law. [5]
(ii) What is standard temperature and pressure ?
(iii) Calculate the percentage of nitrogen in ammonium nitrate. [NH4NOs].
[N = 14, H = 1, O = 16]
Answer:
(i) As per Boyle’s law, the absolute pressure and the volume of a gas are inversely proportional at constant temperature.

(ii) Standard temperature is defined as equal to 0°C, 0°C = 273.15 K.
Standard Pressure is defined as 1 Atm, which is equal to 101. 3kPa or 760 mmHg.

(iii) Molecular mass of NH4NO3 = 23 + 16 + 1 = 40
In ammonium nitrate, there are 2 atoms of nitrogen
Hence, molecular mass = 2 x 40 = 80
Percentage of nitrogen
ICSE Class 9 Chemistry Sample Question Paper 1 with Answers 1

(g) (i) Balance each of the chemical equations given below : [5]
1. FeCl3 + NH4OH → NH4Cl + Fe(OH)3
2. KI + Cl2 → KCl + I2
Answer:
(i) (1) FeCl3 + 3NH4OH → 3NH4Cl + Fe(OH)3
(2) 2KI + Cl2 → 2KCl + I2

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(ii) Identify the substance which matches the description given below :
1. White crystalline substance which sublimes on heating.
2. The gas which turns lime water milky but has no effect on potassium dichromate paper.
3. The metal that cannot displace hydrogen from dilute hydrochloric acid.
Answer:
(1) Iodine crystals
(2) CO2
(3) Metals like Cu, Ag and Au are less reactive than hydrogen; hence these metals cannot displace hydrogen from dilute hydrochloric acid.

(h) Match Column A with Column B.

Column A Column B
(i) Causes hardness in water (A) Calcium oxide
(ii) Causes ozone depletion (B) Concentrated sulphuric acid
(iii) Dehydrating agent (C) Magnesium bicarbonate
(iv) Causes acid rain (D) Chlorofluorocarbon
(v) Drying agent (E) Nitrogen dioxide

Answer:
(i) (C)
(ii) (D)
(iii) (B)
(iv) (E)
(v) (A)

Section – II [40 Marks]
(Attempt any four questions from this section)

Question 2.
(a) The formula of the chloride of a metal ‘M’ is MC12. State the formula of its : [3]
(i) Carbonate (ii) Nitrate (iii) Hydroxide
Answer:
(i) MCO
(ii)M(NO3)2
(iii) M(OH)2

(b) Write balanced chemical equations for each of the following : [3]
(i) Reaction of iron with chlorine.
(ii) Addition of silver nitrate solution to sodium chloride solution.
(iii) Addition of zinc to sodium hydroxide solution.
Answer:
(i) When iron reacts with chlorine, toxic brown fumes are produced and crystals of iron chloride are formed.
2Fe + 3Cl2 → 2FeCl3
(ii) NaCl + AgNOs → AgCl + NaNO3
(iii) \(\mathrm{Zn}+2 \mathrm{NaOH} \stackrel{t^{\circ} \mathrm{C}}{\longrightarrow} \mathrm{Na}_{2} \mathrm{ZnO}_{2}+\mathrm{H}_{2}\)

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(c) Draw the orbit structure for each of the following compounds : [4]
(i) Methane [H = 1, C = 6]
(ii) Megnesium chloride [Mg = 12, Cl = 17]
Answer:
(i) Orbit structure of methane
ICSE Class 9 Chemistry Sample Question Paper 1 with Answers 2

(ii) Orbit structure of magnesium chloride
ICSE Class 9 Chemistry Sample Question Paper 1 with Answers 3
The two electrons lost by a magnesium atom are gained by chlorine atoms to produce a magnesium ion and two chloride ions.

Question 3.
(a) (i) Name the industrial method for the production of hydrogen gas. [3]
(ii) Name the catalyst used in the above process.
(iii) Write the balanced chemical equation for the production of water gas.
Answer:
(i) Electrolysis of water is the industrial method used for the preparation of hydrogen gas.
(ii) Catalyst used in the above process is nickel.
(iii) 2H2O → 2H2 + O2

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(b) (i) What is meant by ‘Group’ in the periodic table ? [3]
(ii) Explain why the elements of the same group exhibit the same chemical behaviour.
(iii) In which group are the inert gases placed in the periodic table ?
Answer:
(i) Vertical columns in the periodic table are called Groups. The periodic table has eighteen vertical columns, comprising of groups (I to VIII and Zero). The groups are further divided into sub-groups thereby making a total of eighteen groups.
(ii) Elements of the same group exhibit same chemical behaviour because their atoms have the same number of electrons in the highest occupied energy level.
(iii) Elements of the Zero group, which is the 18th vertical column, are known as inert gases or noble gases.

(c) A part of the periodic table is shown below with one element missing : [4]

H He
Li Be B C N O F Ne
Na Mg Al Si s Cl Ar
K Cl

(c) Based on the above table, answer the following questions :
(i) Name the element that has duplet structure.
(ii) Name the lightest alkali metal.
(iii) Name the halogen of period 2.
(iv) Identify the missing element.
Answer:
(i) Hydrogen and lithium have duplet structure.
(ii) Lightest alkali metal is lithium.
(iii) Fluorine is the halogen of period 2.
(iv) Missing element is phosphorus

Question 4.
(a) Calculate the volume of gas X at S.T.P. if it occupies 380 litres at ,300 K and 70 cm of mercury. [3]
(b) A gas occupies 70 litres at 27°C. [3]
What volume will it occupy at 273°C, pressure remaining constant ?
(c) Calculate the relative molecular mass of each of the following : [4]
(i) Ammonium dichromate [(NH4)2Cr2O7]
(ii) Hydrated copper sulphate [CuSO4.5H2O]
[H = 1, N = 14, O = 16, S = 32, Cr = 52, Cu = 64]
Answer:
(a) Let the volume at STP is V1 = ?, V2 = 380 litre
P1 = 760 mm of Hg, P2 = 70 cm of Hg
T1= 273 K, T2 = 300 K,
ICSE Class 9 Chemistry Sample Question Paper 1 with Answers 4

Question 5.
(a) (i) What do you understand by the term isotopes ? [3]
(ii) Why do isotopes of an element possess identical chemical properties ?
(iii) Name the isotope of hydrogen which does not have a neutron in it.
Answer:
(i) Isotopes are atoms of the same element having the same numbers of protons (atomic number), but different numbers of neutrons. They have same chemical properties due to the same electronic configuration but different physical properties.

(ii) Isotopes have same chemical properties due to the same electronic configuration but possess different physical properties.

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(iii) 1H, 2H, and 3H are all isotopes of hydrogen and is known as protium which has no neutron in it.

(b) State the type of covelent bonding in the following molecules : [3]
(i) Chlorine
(ii) Nitrogen
(iii) Oxygen
Answer:
(i) Chlorine molecule has a single covalent bond, as one pair of electrons is shared between the atoms.
(ii) Nitrogen has triple covalent bond in it, which is a combination of three single bonds.
(iii) Oxygen has double covalent bond present in it, as it is formed by sharing of two pair of electrons between two atoms.

(c) How would you distinguish between the following pairs of substances on the basis of the chemical tests given in brackets ? [4]
(i) Sodium chloride and potassium chloride (flame test)
(ii) Zinc carbonate and lead carbonate (dry heating)
Answer:
(i) When flame test is performed on sodium chloride, golden yellow colour is imparted to the flame and when seen through a blue glass yellow colour vanishes. When flame test is performed on potassium chloride, violet colour is observed with naked eyes and violet or pink colour is seen through a blue glass.

(ii) When zinc carbonate is dry heated it decomposes to give zinc oxide and yellow colour is seen when hot and white cold, while lead carbonate decomposes to give lead oxide and brown colour is seen when hot and yellow when cold.

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

Question 6.
(a) State if the solubility increases, decreases or remains the same with rise in temperature for each of the following compounds :  [3]
(i) Calcium sulphate
(ii) Potassium nitrate
(iii) Sodium chloride
Answer:
(a) Effect of solubility on various compounds when temperature remains constant:
(i) There is a decrease in solubility of calcium sulphate with further rise in temperature.
(ii) Potassium nitrate shows considerable increase in solubility with further rise in temperature.
(iii) Solubility of sodium chloride increases only a little, with increase in temperature.

(B) (i) What is the difference between temporary hard water and permanent hard water ? [3]
(ii) Write a balanced chemical equation for the removal of :
1. Permanent hardness
2. Temporary hardness
Answer:

Temporary hard water Permanent hard water
Water that contains only hydrogen carbonates of calcium and magnesium is called temporary water. Water containing sulphates and chlorides of magnesium and calcium is called permanent hard water.
Temporary hardness of water is removed by boiling, by addition of lime and by addition of washing soda. To remove permanent hardness of water it is treated with a calculated quantity of soda ash.
Temporary hardness is called as carbonate or alkaline hardness. It is also known as non-carbonate or non alkaline hardness.

(ii) 1. Permanent hardness :
MgSO4 + Na2CO3 + Ca(OH)2 → Mg(OH)2 + CaCO3 + Na2SO4
2. Temporary hardness :
Ca(HCO3)2 → CaCO3 + H2O + CO2
2Al + Fe2O3 →Al2O3 + 2Fe

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(c) Classify each of the following reactions as combination, decomposition, displacement or double displacement:  [4]
(i) 2Al + Fe2O3 → Al2O3 + 2Fe
(ii) 2KClO3 → 2KCl + 3O2
(iii) BaCl2 + Na2SO4 → BaSO4 + 2NaCl
(iv) CaO + H2O → Ca(OH)2
Answer:
(i) This is an example of displacement reaction where a more reactive element i.e., aluminium displaces a less reactive element i.e., iron to form aluminium oxide.

(ii) 2KClO3→ 2KCl + 3O2 is an example of decomposition reaction where potassium chlorate decomposes to give potassium chloride and oxygen.

(iii) BaCl2 + Na2SO4 → BaSO4 + 2NaCl is an example of double decomposition (precipitation reaction) where barium chloride and sodium sulphate react to form an insoluble white ppt. BaSO4 and sodium chloride.

(iv) CaO + H2O → Ca(OH)2 is an example of combination reaction where calcium oxide and water combines to form calcium hydroxide.

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

Question 7.
Complete the following table : [6]

Element Mass
Number
Atomic
Number
Number of Electrons Number of  Protons Number of Neutrons
Phosphorous 31 15 ………….. …………. ………….
Potassium …………. …………. 19 …………. 20

Answer:

Element Mass
Number
Atomic
Number
Number of Electrons Number of  Protons Number of Neutrons
Phosphorous 31 15 15 15 16
Potassium 39 19 19 19 20

Number of electrons = Number of protons = Atomic number
Mass number = Number of protons + Number of neutrons

(b) Write the electronic configuration of the following :
(i) \({ }_{20}^{40} \mathrm{Ca}\)
(ii) \({ }_{16}^{32} \mathrm{~S}\)
Answer:
(i) Electronic configuration of Calcium is :
Is2 2s2 2p6 3s2 3p6 4s2
(ii) Electronic configuration of Sulphur is :
Is2 2s2 2p6 3s2 3p4

ICSE Class 9 Chemistry Sample Question Paper 1 with Answers

(c) State the valency of the element having : [2]
(i) 6 electrons in the valence shell.
(ii) the electronic configuration of : 2, 3
Answer:
(i) The element which has 6 electrons in its valence shell is sulphur and its valency is 2.
(ii) The element whose electronic configuration is 2, 3 is Boron and its valency is 3.

ICSE Class 9 Chemistry Question Papers with Answers

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