Frank ICSE Class 10 Chemistry

Frank ICSE Solutions for Class 10 Chemistry – Metals and Non-metals

by

Frank ICSE Solutions for Class 10 Chemistry – Metals and Non-metals

PAGE NO : 151
Solution 1:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 1

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 2

Solution 3:
Metal which exist in liquid state is mercury.
Non-metal which exist in liquid state is bromine.
Concept Insight: Metals are usually solid while non-metals exist in all the three states.

Solution 4:
The most abundant metal in the earth’s crust is aluminium and the most abundant non-metal in the earth’s crust is oxygen.

Solution 5:

  1. Metals.
  2. Non-metals.
  3. Platinum and Gold.
  4. Potassium and Sodium.
  5. Potassium, Sodium and Calcium.
  6. Iron.
  7. Potassium and Sodium.
  8. Platinum.
  9. Platinum and Gold.
  10. Mercuric oxide (HgO) and Silver oxide (Ag2O).
  11. Potassium hydroxide (KOH) and Sodium hydroxide (NaOH).
  12. Potassium carbonate (K2CO3) and Sodium carbonate (Na2CO3).
  13. Potassium carbonate (K2CO3) and Sodium carbonate (Na2CO3).
  14. Potassium nitrate (KNO3) and Sodium nitrate (NaNO3).
  15. Mercuric nitrate (Hg(NO3)2) and silver nitrate (AgNO3)

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 3

Solution 7:

  1. Fe < Zn < Mg < Na.
  2. Na = Al < Cu<Fe
  3. Ca >Mg > Fe > Cu.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 4

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Frank ICSE Solutions for Class 10 Chemistry – Electrolysis

by

Frank ICSE Solutions for Class 10 Chemistry – Electrolysis

PAGE NO : 131
Solution 1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 1

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 2

Solution 3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 3

Solution 4:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 4

Solution 5:
Three appilications of electrolysis are:

  1. Electro plating with metals
  2. Electrofining of metals
  3. Extraction of metals

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 6
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 7

Solution 7:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 8

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 9

Solution 9:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 10

PAGE NO : 132

Solution 10:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 11

Solution 11:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 12

Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 13

Solution 13:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 14

Solution 14:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 15

Solution 15:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 16

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 17

Solution 17:
The main appilications of electrolysis are:

  1. Electro plating with metals
  2. Electrofining of metals
  3. Extraction of metals

Solution 18:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 18

Solution 19:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 19

Solution 20:

  1. Na2CO3
  2. NH3
  3. Graphite, Cu electrode
  4. NH4+
  5. Graphite

PAGE NO : 133
Solution 1994-1:

  1. The article to be plated must be made Cathode.
  2. The ions of the metal which is to be electroplated must be present in the electrolyte.
  3. The metal to be plated on the article must be made anode. It needs to be periodically replaced.

Solution 1994-2:
The passage of electricity through an electrolyte occurs through ions furnished by the electrolyte where as the passage of electricity through a copper wire occurs through electrons.

Solution 1995-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 20

Solution 1995-2:
It is the process of decomposition of an electrolyte in the molten or aqueous state by discharge of ions at the electrodes on the passage of an electric current.

Solution 1995-3:
Pure water does not conduct electricity because the degree of ionization is low. Thus to make it a good conductor of electricity acid is added to it which will increase the degree of ionization.

Solution 1996-1:
Substance which contain

  1. Ions only:- HCl
  2. Molecules only:- Petrol
  3. Both ions and molecules:- CH3COOH

Solution 1996-2:

  1. Electrolyte is a compound which either in aqueous solution or in molten state allows an electric current to pass through it and is accompanied by discharge of ions and finally into neutral atoms at the two electrodes.
  2. Non- electrolyte are substances which do not conduct electricity in fused or aqueous state. They contain only molecules and do not ionize. For example: petrol, alcohol.
  3. If the electrolyte is described as ‘strong electrolyte’ it means it completely dissociates into its constituting ions in aqueous solution.

Solution 1996-3:

  1. As for every copper ion discharged at the cathode, an ion of copper is formed at the anode which goes into the solution .Since atoms of copper are deposited at the cathode, the cathode becomesthicker and as the atoms of copper from the anode change into ions of copper, the anode becomes thinner.
  2. When platinum rods are used as electrodes, then x the blue colour of copper sulphate solution fades and sulphuric acid is formed. This is because oxygen is liberated at anode and copper metal is deposited at cathode
  3. Practical application of electrolysis of copper sulphate solution: This is the basis for purification of copper.
    Other metals like Zinc, Nickel, Silver .Lead can also be purified.

Solution 1997-1:
Lead Bromide should be in the molten state if it has to conduct electricity.

Solution 1997-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 21

Solution 1997-3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 22

Solution 1998-1:

  1. Electrolyte
  2. Nickel
  3. Cathode
  4. Anode
  5. Cations

PAGE NO : 134
Solution 1999-1:
The electrolysis of lead bromide liberates lead at cathode and bromine at anode.

Solution 1999-2:
When a fused metallic chloride is electrolyzed, the metal is obtained at cathode.

Solution 2000-1:

  1. Strong electrolytes – dilute hydrochloric acid, dilute sulphuric acid, Ammonium chloride
  2. Weak electrolyte – Acetic acid, Ammonium hydroxide
  3. Non-electrolytes – Carbon tetrachloride

Solution 2002-3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 23

Solution 2002-1:

  1. molecules.
  2. will not

Solution 2002-2:

  1. When sulphuric acid is added to water it becomes good conductor as addition of sulphuric acid causes dissociation of water molecules into H+ and OH– ions which are then responsible for conduction of electricity by pure water. The water thus obtained is called acidified water.
  2. Cathode, Anode

Solution 2003-1:
electricity, chemical

Solution 2004-2

  1. Molecules are found in a liquid compound which is a non-electrolyte.
  2. Non ionized molecules;
  3. H+ and X– particles will be present in dilute solution.
  4. Loss, Gain
  5. The ions of the metal which is to be electroplated on the article must be present in a solution.
  6. Redox reaction is one in which oxidation and reduction occurs simultaneously.
  7. Similarly in case of electrolysis:
    • At cathode: The cations gain electron and become neutral. As the electrons are gained the ion is said to be reduced.
    • At anode: The anions lose electron to form neutral atoms. As the electrons are lost the ion is said to be oxidized.
      Hence in electrolysis also the oxidation and reduction occurs hence it is an example of Redox reaction.

Solution 2004-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 24

PAGE NO : 135
Solution 2005-1:

  1. Copper metal is solid and has no mobile ions whereas an electrolyte should dissociate into oppositely charged ions to conduct the electric current.
  2. Hydrogen is released at the cathode when acidulated water is electrolyzed.
  3. In sodium chloride, Na+ and Cl– ions are not free to carry the electric current.
  4. (a) Reduced
    (b) Higher

Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 25

Solution 2006-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 26

Solution 2007-1:

  1. Molten ionic compound – Strong electrolyte
  2. Carbon tetrachloride- Non-electrolyte
  3. An aluminium wire- Metallic conductor
  4. A solution containing solvent molecules, solute molecules and ions formed by the dissociation of solute molecules- weak electrolyte
  5. A sugar solution with sugar molecules and water molecules- Non-electrolyte

Solution 2007-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 27

PAGE NO : 136
Solution 2008-1:
(d) Lead is deposited at the cathode

Solution 2008-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 28

Solution 2009–2:
Mg (OH)2 as it is basic while rest are amphoteric.

Solution 2009–3:
Molten Lead bromide conducts electricity.

Solution 2009-4:

  1. Nickel ions move towards cathode.
  2. Nickel ions.

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Frank ICSE Solutions for Class 10 Chemistry – Mole Concept And Stoichiometry

by

Frank ICSE Solutions for Class 10 Chemistry – Mole Concept And Stoichiometry

PAGE NO : 103
Solution 1:

  1. Gay-Lussac’s law: It states that ‘when gases react, they do so in volumes which bear a simple ratio to one another, and also to the volume of the gaseous product, provided all the volumes are measured at the same temperature and pressure’.
  2. Avogadro’s law : It states that ‘Under the same conditions of temperature and pressure, equal volumes of all gases contain the same number of molecules’.

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 1

Solution 3:
When stating the volume of a gas, the pressure and temperature should also be given because the volume of a gas is highly susceptible to slight change in pressure and temperature of the gas.

Solution 4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 2

Solution 5:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 3

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 4

Solution 7:

  1. Gram atom: “The quantity of the element which weighs equal to its gram atomic mass is called one gram atom of that element”.
    For example: The gram atomic mass of hydrogen is 1g. So, 1g of hydrogen is 1 gram atom of hydrogen.
  2. Gram mole: “A sample of substance with its mass equal to its gram molecular mass is called one gram molecule of this substance or one gram mole”.
    For example: Gram molecular mass of oxygen is 32 g. So One gram mole of oxygen is 32g.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 5

Solution 9:
Empirical formula:“Empirical formula of a compound is the formula which gives the number of atoms of different elements present in one molecule of the compound, in the simplest numerical ratio”.
Molecular formula: “Molecular formula of a compound denotes the actual number of atoms of different elements present in one molecule of the compound”.

Solution 10:

  1. The empirical formula of C6H6 is: CH
  2. The empirical formula of C6H12O6 is: CH2O.
  3. The empirical formula of C2H2 is: CH
  4. The empirical formula of CH3COOH is: CH2O.

Solution 11:
Three pieces of information conveyed by the formula H2O is that:

  1. It shows that there are 2 hydrogen atoms and 1oxygen atoms present in H2O.
  2. The hydrogen and oxygen atoms are present in simplest whole number ratio of 2:1.
  3. It represents one molecule of compound water.

Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 6

Solution 13:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 7

PAGE NO : 104

Solution 14:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 8

Solution 15:

  1. Na2SO4.10H2O.
  2. C6H12O6.

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 9

Solution 17:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 10

Solution 18:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 11

Solution 19:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 12

Solution 20:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 13

Solution 21:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 14

Solution 22:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 15

Solution 23:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 16

Solution 24:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 17

PAGE NO : 105
Solution 25:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 18

Solution 26:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 19

Solution 27:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 20

Solution 28:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 21

Solution 29:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 22

Solution 30:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 23

Solution 31:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 24

Solution 1996-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 25

Solution 1996-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 26

Solution 1996-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 27

Solution 1996-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 28

PAGE NO : 106
Solution 1997-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 29

Solution 1997-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 30

Solution 1997-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 31

Solution 1997-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 32

Solution 1998-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 33

Solution 1998-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 34

Solution 1999-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 35

PAGE NO : 107

Solution 1999-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 36

Solution 1999-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 37

Solution 2000-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 38

Solution 2000-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 39

Solution 2000-1:
Gay – Lussac proposed this law.

Solution 2001-2:
Molecular mass of ethane = 30
According to Gay-Lussac’s law:
2 vol. of C2H6 requires= 7 vol. of oxygen
Vol. of C2H6 = 2 vol. = 100 L
Vol. of oxygen required = 7 vol. =350 L

Solution 2001-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 40

PAGE NO : 108
Solution 2001-4:
The term is vapour density.

Solution 2001-5:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 41

Solution 2001-6:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 42

Solution 2001-7:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 43

Solution 2002-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 44

Solution 2002-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 45

Solution 2002-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 46

Solution 2003-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 47

Solution 2004-1:

Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 48

PAGE NO : 109
Solution 2004-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 49

Solution 2005-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 50

Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 51

Solution 2006-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 52

PAGE NO : 110
Solution 2006-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 53

Solution 2006-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 54

Solution 2007-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 55

Solution 2007-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 56

Solution 2008-1:
The gas laws which relates the volume of a gas to the number of molecules of the gas is avogadro’s law

PAGE NO : 111
Solution 2008-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 57

Solution 2008-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 58
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 59

Solution 2009-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 60

Solution 2009-3:
The correct statement is that equal volumes of all gases under identical conditions contain the same number of molecules.

Solution 2009-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 61

Solution 2009-1:
The relative molecular mass of the gas is 10.

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Frank ICSE Solutions for Class 10 Chemistry – Analytical Chemistry

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Frank ICSE Solutions for Class 10 Chemistry – Analytical Chemistry

PAGE NO : 75
Solution 1:

  1. Cuprous salts = Colourless
  2. Cupric salts = Blue
  3. Aluminium salts = Colourless
  4. Ferrous salts= Light green
  5. Ferric salts = Yellow
  6. Calcium salts = Colourless

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 1

Solution 3:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 2

Solution 4:
K2SO4.

Solution 5:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 3

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 4

Solution 7:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 5

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 6

Solution 9:
Examples of amphoteric hydroxides are: Zn(OH)2, Al(OH)3.

Solution 10:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 7

Solution 11:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 8

PAGE NO : 76
Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 9

Solution 13:
The chloride of a metal which is soluble in excess of ammonium hydroxide is zinc chloride i.e. ZnCl2.

Solution 14:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 10

Solution 15:

  1. PbO
  2. Al2O3
  3. Na2ZnO2

Solution 16:

  1. transition, Cr3+, Fe2+, MnO44-.
  2. Zn(OH)2
  3. NH4Cl
  4. Al2O3, Al
  5. NH4OH

Solution 1992-1:

  1. Addition of KCN
  2. Addition of excess of NaOH.
  3. Addition of excess ofNH4OH

Solution 1993-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 11

PAGE NO : 77
Solution 1995-1:

  1. The metal ion present in solution A is Pb2+
    .
  2. The cation present in solution B is Cu2+. The probable colour of solution B is blue.

Solution 1996-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 12

Solution 1996-2:
 The solutions for the tests will be prepared by dissolving the given powders separately in water.

  1. Solution of Calcium carbonate:
    Calcium carbonate is CaCO3 and contains Ca2+ ions. Sodium hydroxide solution NaOH can be used to identify Ca2+ since its addition to calcium carbonate solution will give white precipitates of Ca(OH)2 which are sparingly soluble in excess of NaOH.
  1. Solution of Lead carbonate:
    Lead carbonate is PbCO3and contains Pb2+ ions. Ammonium hydroxide solution NH4OH can be used to identify Pb2+ since its addition to lead carbonate solution will give white precipitates of Pb(OH)2 which are insoluble in excess of NH4OH.
  2. Solution of Zinc carbonate:
    Zinc carbonate is ZnCO3 and contains Zn2+ ions. Sodium hydroxide solution NaOH can be used to identify Zn2+ since its addition to zinc carbonate solution will give white gelatinous precipitates of Zn(OH)3 which are soluble in excess of NaOH.

Solution 1996-3:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 13

Solution 1997-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 14

Solution 1998-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 15

Solution 1999-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 16

Solution 2000-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 17

PAGE NO : 78
Solution 2001-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 18

Solution 2003-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 19

Solution 2003-2:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 20

Solution 2004-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 21

PAGE NO : 79
Solution 2005-1:

  1. B and E (Iron (II) sulphate and Magnesium sulphate)
  2. C and F (Iron (III) chloride and Zinc chloride)
  3. D (Lead nitrate)
  4. A (Copper nitrate)
  5. F (Zinc chloride)

Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Analytical Chemistry 22

Solution 2009-1:
C ( Aluminium oxide)

Solution 2009-2:

  1. P is Ferric chloride
  2. Q is an ammonium salt
  3. R is ferrous sulphate

Solution 2009-3:

  1. When BaCl2
  2.  solution is added to the given solution ZnSO4
  3. gives a white precipitate while no precipitate is obtained with ZnCl2 solution.
  4. When NaOH solution is added to the given solution, iron (II) chloride gives dirty green precipitate while reddish brown precipitate is obtained with iron(III) chloride.

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Frank ICSE Solutions for Class 10 Chemistry – Study Of Acids, Bases and Salts

by

Frank ICSE Solutions for Class 10 Chemistry – Study Of Acids, Bases and Salts

PAGE NO : 62
Solution 1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 1

Solution 2:

  1. (i) Hydrogen chloride HCl
    (ii) Nitric acid HNO3
  2. (i) Carbonic acid H2CO3
    (ii) Oxalic acid (COOH)2
  3. (i) Sulphuric acid H2SO4
    (ii) Hydrogen chloride HCl
  4. (i) Carbonic acid H2CO3
    (ii) Acetic acid

Solution 3:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 2

Solution 4:

  1. The pH of a solution is defined as the negative logarithm (base 10) of the hydronium ion concentration present in the solution.
    pH =-log10 [H3O+]
  2. The three applications of pH scale are:
    • It is used to determine the acidic or basic nature of the solution.
    • It is used to determine hydronium ion concentration present in the solution.
    • It is used to find out neutrality of the solution.

Solution 5:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 3

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 4

Solution 7:

  1. Base in solution furnishes the ions:
    Hydroxide ion/ oxide ion and a metallic ion.
  2. A weak alkali furnishes the ions:
    Hydroxide ion and metallic ion and molecules of weak alkali./
  3. An acid in a solution furnishes the ions:
    Hydronium / Hydrogen ion and a negative ion.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 5

PAGE NO : 63
Solution 9:

  1. CaO
  2. NaOH
  3. CuO
  4. Cu[(OH)2]
  5. H2CO3
  6. Ferric hydroxide [Fe (OH)3].
  7. CuO
  8. NH3

Solution 10:
Anhydrous hydrogen chloride is not an acid but its aqueous solution is a strong acid because anhydrous means without water and we know that the property of acidity is shown by a substance only when it is dissolved in water or its aqueous solution is prepared.

Solution 11:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 6

Solution 12:
Strength of an acid measures the ease with which the acid can ionize to produce hydrogen or hydronium ions when dissolved in water. Those acids which can easily ionize to form hydrogen ions are called strong acids while those which can partially ionize to form hydrogen ions are called weak acids.
Strength of an acid depends upon many factors such as:

  1. Molecular structure of the acid
  2. The temperature
  3. Properties of the solvent

Solution 13:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 7

Solution 14:
Solution B with pH value 9 will give pink colour with phenolphthalein.
Concept Insight: Bases give pink colour with phenolphthalein because a base will abstract two protons from phenolphthalein and the resulting phenolphthalein ion provides pink colour to the solution.

Solution 15:
Two indicators for identification of acid are methyl red and Thymol blue.

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 8

Solution 17:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 9

Solution 18:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 10

Solution 19:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 11

Solution 20:

  1. Efflorescence: It is the phenomenon by which hydrated salts on exposure to dry air, lose their water of crystallization and crumble to powder.
  2. Hygroscopy: It is the phenomenon by which substances absorb moisture from air, but only sufficiently so as to become wet.
  3. Water of crystallization: It is the fixed amount of water that is present in a crystal as an integral part of its constitution. Hydrated salts are salts having water of crystallisation.

Solution 21:
Deliquescence is the phenomenon by which certain salts absorb moisture from air, lose their water of crystallization and dissolve in it to form a saturated solution.
The substances which exhibit deliquescence are called deliquescent.
For example Caustic soda NaOH, Caustic potash KOH.

Solution 22:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 12

Solution 23:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 13

Solution 24:

  1. Common salt gets wet during rainy season because the commercially available salt contains impurities, like magnesium chloride, which are deliquescent substances. These absorb moisture from atmosphere and make the table salt wet.
  2. (i)  Na2CO4.10H2O = Washing soda
    (ii) MgSO4.7H2O = Epsom salt
    (iii)CuSO4.5H2O = Blue vitriol
    (iv) ZnSO4.7H2O = White vitriol

PAGE NO : 64
Solution 1996-1:

  1. pH of a solution having pH 7 can be increased by adding a base to it such as NaOH.
  2. pH can be decreased by adding an acid such as HCl to it.
    If a solution changes colour of litmus from red to blue, it shows that its pH is above 7.

Solution 1996-2:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 14

Solution 1996-3:

  1. Zinc sulphate = Zinc and dilute sulphuric acid
  2. Copper sulphate = Copper oxide and dilute sulphuric acid
  3. Sodium sulphate = Sodium carbonate solution and dilute sulphuric acid
  4. Lead sulphate = Lead carbonate and dilute sulphuric acid

Solution 1997-1:
The term acid salt means the salt formed by partial replacement of the hydrogens present in the acid by metallic or ammonium ions.
For example: NaHCO3

Solution 1997-2

  1. pH scale is used to express the acidic or basic nature of solution.
  2. pH of pure water is 7 since it does not have any impurities.
  3. (a) A soluble oxide of A will have pH less than the pH of pure water i.e. below 7.
    (b) A solution of ‘B’ will have more pH than pure water i.e. above 7.

Solution 1997-3:

  1. Water of crystallization: It is the fixed amount of water that is present in a crystal as an integral pat of its constitution. Compounds having water of crystallization are called hydrous salts.
    For example: Sodium carbonate Na2CO3 has 10 molecules of water present as water of crystallization Na2CO3.10H2O
  2. Anhydrous: Hydrous salt on heating lose their water of crystallization, such salts are then called anhydrous.
    For example:Na2CO3.10H2O on losing 10 molecules of water forms Na2CO3

Solution 1997-4:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 15

Solution 1998-1:

  1. Water of cystallization.
  2. White.
  3. Efflorescence.
  4. Sodium chloride.

Solution 1998-2:
Those acids which ionize partially in aqueous solution and thus they contain ions as well as molecules of the acid. Organic acid such as CH3COOH, is a weak acid.

Solution 1998-3:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 16

PAGE NO : 65
Solution 1998-4:
The name and formula of the acid salt which gives sodium ions and sulphate ions in solution is Sodium hydrogen sulphate NaHSO4

Solution 1999-1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 17

Solution 2000-1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 18

Solution 2001-1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 19

PAGE NO : 66
Solution 2002-1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 20

Solution 2003-1:

  1. Hydronium, positive.
  2. Acid, metal.

Solution 2003-2:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 21

Solution 2004-1:
methods for preparation:

  1. Preparation of copper(II) chloride.
    Action of an acid on an oxide or carbonate
  2. Preparation of iron(III) chloride.
    Direct combination
  3. Preparation of iron (II) chloride.
    Action of an acid on a metal
  4. Preparation of lead (ii) chloride
    Precipitation (double decomposition)
  5. Preparation of sodium chloride
    Neutralization of an alkali by an acid.

Solution 2005-1:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 22

PAGE NO : 67
Solution 2005-2:
Positive, hydroxyl, Salt, Neutralization.

Solution 2005-3:
When neutral litmus solution is added to sodium hydrogen carbonate solution, litmus solution turns red

Solution 2006-1:

  1. From pink to colourless.
  2. From orange to pink.
  3. From colourless to red.

Solution 2007-1:

  1. Hydronium
  2. Hydroxide
  3. Salt
  4. Water
  5. Hydrogen

Solution 2007-2:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 23

Solution 2008-1:

  1. Complex salt.
  2. Alkali.

Solution 2009-1:
Acidified potassium dichromate paper

PAGE NO : 68
Solution 2009-2:

  1. Solution B.
  2. Solution A.
  3. Solution B
  4. Solution of ammonium hydroxide NH4OH is a weak alkali.

Solution 2009-3:
Frank ICSE Solutions for Class 10 Chemistry - Study Of Acids, Bases and Salts 24

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Frank ICSE Solutions for Class 10 Chemistry – Chemical Bonding

by

Frank ICSE Solutions for Class 10 Chemistry – Chemical Bonding

PAGE N0 : 39
Solution 1:
Chemical bond: A chemical bond may be defined as the linkage that stands for the force which actually holds the atoms together within the molecule.
Chemical bonding: The phenomenon during which a chemical bond is formed is called chemical bonding.

Solution 2:
Atoms combine to attain the electronic configuration of nearest inert gases as the atoms of inert gases are very stable having 8 electrons or duplet (or 2 electrons in case of helium atom) in their outermost shell.

Solution 3:
Electrovalent compounds: The chemical compounds containing electrovalent bonds are called electrovalent or ionic compounds.
For example: Sodium chloride (NaCl).
Covalent compounds: The chemical compound, formed as a result of mutual sharing of electrons or electron pairs thereby establishing a covalent bond is called a covalent or molecular compound.
For example: Hydrogen molecule (H2)

Solution 4:
The conditions for the formation of an electrovalent bond are:

  1. Low ionization energy of electropositive atom
  2. High electron affinity of the electronegative atom.
  3. Large electronegativity difference.
  4. High lattice energy.
    Concept Insight:

    • Lower is the ionization energy of atom, higher is its tendency to lose electron to form a cation and form ionic bond.
    • Higher the value of electron affinity of an atom, greater will be its tendency to form anion and form ionic bond.
    • If the electronegativity difference of two elements is higher, more easy will be the transfer of electrons and hence more chances of ionic bond formation.
    • Lattice energy is the energy released when positive and negatively charged atoms called ions come closer to form a crystal because the attractive forces among the oppositely charged ions tend to decrease the energy of the system. Higher is the lattice energy, greater will be the ease of formation of the compound.

Solution 5:

Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 1

Solution 6:
Hydrogen chloride has a polar covalent bond because in hydrogen chloride the higher electronegativity of chlorine atom attracts the shared electron pair towards itself. As a result, the chlorine atom gets a partial negative charge while the hydrogen atom gets a partial positive charge. Hence such a covalent bond with charge separation is called polar covalent bond.
While methane has a non polar covalent bond because in case of methane molecule the shared electron pairs are at equal distance from the carbon and hydrogen atoms, because neither the carbon atom nor the hydrogen atom has enough electronegativity difference between each other to attract the shared pairs of electrons towards itself. Hence no charge separation occurs in the covalent bond due to which it is called non polar covalent bond.
Concept Insight: When a covalent bond is formed between the atoms of the same elements of equal electronegativity then the electron pairs are shared equally between the atoms and the bond so formed is called non polar covalent bond. On the other hand, if the covalent bond is formed between atoms of different elements, with difference in electro negativity, the electrons are not shared equally between the atoms. The more electronegative atom pulls the bonded pair of electrons towards itself and acquires negative charge while the other less electro negative atom acquires positive charge and the bond becomes polar covalent bond.

Solution 7:
In terms of electron transfer, oxidation is defined as the phenomenon in which an atom loses electron to form a positively charged cation while reduction is defined as the phenomenon in which an atom gains electron to form a negatively charged ion called anion.
During formation of ionic bond one atom undergoes oxidation while another atom undergoes reduction.

PAGE NO : 48
Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 2

Solution 9:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 3

Solution 10:

  1. Sodium chloride dissolves in water because it is an ionic compound and water is also a polar covalent compound. Water decreases the electrostatic forces of attraction among the sodium and chloride ions due to which these ions become free in water, hence sodium chloride dissolves.
    On the other hand, carbon tetra chloride has non polar covalent bond and water has polar covalent bond. Hence, water is unable to break the non polar covalent bond of carbon tetra chloride. So it is insoluble in water
  2. Helium does not form He2 molecule as it has its outermost shell complete i.e. two electrons in its valence shell. Due to this complete valence shell helium atom is very stable hence does not participate in chemical bonding to form  He2 molecule.
  3. Pure water does not conduct electricity because it has a polar covalent molecule hence does not have ions in it which can conduct electricity.
    On adding sodium chloride to pure water, sodium chloride breaks apart into sodium and chloride ions because water being polar decreases the strong forces of attraction among sodium and chloride ions. Now, pure water has ions present in it which can conduct electricity.
  4. Cl2 is a non polar molecule because the bond is between same atoms that is chlorine with zero electronegativity difference among them. So the shared electron pair is attracted equally by the two chlorine atoms hence there is no separation of charges in the bond formed so the chlorine molecule is non polar.
  5. In case of HCl the bond is formed between two different atoms that is hydrogen and chlorine with enough electro negativity difference so that the shared electron pair is attracted towards more electronegative chlorine atom which acquires partial negative charge while the hydrogen atom acquires partial positive charge hence HCl is a polar molecule.
  6. Metals have low ionization energy due to which they can lose their outermost electrons easily to form positive metallic ions hence metals are electropositive.
    For example Sodium metal always form Na+ions, Potassium forms K+ ions etc.

Solution 11:

  1. (i) when the electro negativity difference between the two atoms is high then the bond formed will be purely ionic.
    (ii) When the electro negativity difference between the two atoms is low then the bond formed will be polar covalent bond.
    (iii) When the electro negativity difference between the two atoms is zero then the bond formed will be purely covalent.
  2. Ionic compounds = NO, NH4Cl, NH4NO3
    Covalent compounds = N2, NH2 , NO
    Polar compounds = NCl3

Concept Insight: Electro negativity difference between the bonded atoms determines the ease of transfer of electrons between the atoms. On the basis of extent of transfer of electrons between the two atoms the bond will be ionic, covalent or polar.

Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 4

Solution 13:

  1. MgCl2, CaCl2.
  2. Urea, Glucose.
  3. CH4, benzene.
  4. SO2, H2S
  5. H2, N2

Solution 14:
The necessary conditions for the formation of covalent molecule are:

  1. Number of valence electrons: Both the participating atoms should have four or more valence electrons in their valence shell.
  2. Equal electro negativities: The combining atoms should have equal electro negativities so that no transfer of electrons takes place.
  3. Equal electron affinities: The combining atoms should also have equal electron affinities i.e. equal attraction for electrons.
  4. Ionization energy: It should be high for both the atoms so that there is no chance of removal of electrons.
  5. High nuclear charge and small inter nuclear distance: Both these conditions favor the formation of covalent bond because during the formation of a covalent bond the electron density gets concentrated between the nuclei of the combining atoms and this electronic charge is responsible for holding the two nuclei together.
    The properties of covalent compounds are:
  6. Nature: They are generally volatile liquids or gases. Some may be gases like urea, sugar etc.
  7. Low melting and boiling points: Since the intermolecular forces of attraction are weak, very small amount of heat energy is required to overcome these forces hence their melting and boiling points are low.
  8. Electrical conductivity: Since covalent compounds are made up of molecules and not ions, so they do not conduct electricity.
  9. Solubility: These are insoluble in water but soluble in organic solvents.
  10. Ionization in solution: These do not ionize when dissolved in water except some polar covalent compounds like HCl.
  11. Molecular reactions: These participate in reactions as a molecule so the reactions are called molecular reactions. These are slow reactions.

Solution 15:
Coordinate bond: The bond formed between two atoms by a pair of electrons, provided entirely by one of the combining atoms, is called a coordinate bond or dative bond.
Conditions for the formation of coordinate bond:

  1. One of the two atoms must have at least one lone pair of electrons.
  2. Another atom should be short of at least a lone pair of electrons.

Solution 16:
Lone pair: A pair of electrons which is not shared with any other atom is known as the lone pair of electrons.
For example in NH3, Nitrogen has a lone pair of electrons which is not shared with any hydrogen atom.
Shared pair: A pair of electrons which is shared with other atoms to form a bond is known as shared pair of electrons.
For example in HCl the pair of electrons responsible for bond formation between H and Cl is called shared pair.

Solution 17:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 5

Solution 18:

  1. The forces of attraction between the molecules of covalent compounds are weak because the molecules are neutral. So, they are generally gases or liquids or soft solids.
  2. Covalent compounds have low melting and boiling point because the intermolecular forces of attraction among the molecules of covalent compounds are weak. Hence very small amount of heat energy is required to overcome the attraction between the molecules.
  3. On the basis of principle like dissolves like we can interpret the insolubility of non polar covalent compounds. Since water is a polar covalent compound that is it has positively and negatively charged ends but the non-polar covalent compounds do not have any kind of charge separation. So water molecules are unable to interact with the molecules of non polar compound and break apart the intermolecular forces of attraction among non-polar molecules making them soluble in water.
  4. Polar covalent compounds are good conductors of electricity because when these are dissolved in water, they ionize and act as electrolyte to produce ions which are responsible for conduction of electricity.
    Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 11
    For example polar covalent compound HCl in water behaves as:
    These hydronium and chloride ions produced on dissolution of HCl in water are responsible for conduction of electricity.

PAGE NO : 41
Solution 2002-1:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 6

Solution 2004-1:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 7

Solution 2005-1:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 8

PAGE NO : 42
Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 9

Solution 2006-2:

  1. (b)
  2. (a)

Solution 2007-1:
Frank ICSE Solutions for Class 10 Chemistry - Chemical Bonding 10

Solution 2008-1:
ionises when dissolved in water

Solution 2008-2:

  1. Covalent bond.
  2. Co-ordinate bond

Solution 2009-1:

  1. solid
  2. low

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Frank ICSE Solutions for Class 10 Chemistry – Periodic Properties and Variation of Properties

by

Frank ICSE Solutions for Class 10 Chemistry – Periodic Properties and Variation of Properties

PAGE NO : 16
Solution 1:
Modern periodic law states that the physical and chemical properties of elements are a periodic function of their atomic numbers i.e., if the elements are arranged in the order of their atomic numbers, the elements with similar properties are repeated after definite regular intervals.
Concept Insight: The elements are characterized by their atomic number as well as atomic weight. Modern periodic law uses atomic number which is number of protons or number of electrons present in an atom of an element.

Solution 2:
Modern periodic table consists of eighteen groups and seven periods.
Concept Insight: Classification of elements on the basis of increasing atomic number is known as Modern Periodic Table. The vertical columns are called groups and the horizontal rows are called periods.

Solution 3:
The recurrence of similar properties of elements after certain regular intervals when they are arranged in the order of increasing atomic numbers is called periodicity.
Concept Insight: Periodicity in properties is due to the repetition of similar outer electronic configuration of elements at certain regular intervals.

Solution 4:
In general, the elements belonging to a group have the same number of valence electrons .For example, all the group 1 elements have valency one since they have only one electron in their outermost shell.
In general, the elements belonging to a period do not have same valency but their valence shell remains the same. For example, second period has 8 elements with atomic number 3 to 10 but in all of them the valence electrons are present in shell number two.
Concept Insight: For elements in a group the number of electrons present in the outermost shell is the same and therefore the elements have same valency and or elements in a period number of electrons present in the outermost shell of elements in a period increase from left to right but the shell does remains the same.

Solution 5:
Fluorine has lower electron affinity than chlorine because of the small size of fluorine which results in stronger repulsion between the electron and the electrons already present in the atom of fluorine. Hence the energy released in accepting an electron is lesser in fluorine than that of chlorine.
Concept Insight: For answering this question you should recall that electron affinity is the energy released when an electron is added to an isolated gaseous atom to form an anion. Due to small size of fluorine atom, the valence shell is already crowded, hence when an electron is added to a fluorine atom in gaseous state there occurs strong repulsion between the added electron and those already present in the atom hence less amount of energy is released.

Solution 6:

  1. The element with highest first ionization energy: Neon (Ne)
  2. The element with highest electro negativity: Fluorine (F)
  3. The element with largest atomic size: Lithium (Li)
  4. The most reactive non-metal: Fluorine
  5. The most reactive metal: Lithium
  6. Concept Insight:
    • Neon has highest ionization energy since it is a noble gas and has its octet complete which makes it very stable.
    • Fluorine has highest electronegativity as we know that electro negativity increases along a period due to decreasing atomic size and increasing nuclear charge.
    • Lithium has the largest atomic size since it is an alkali metal i.e., belongs to group 1 and we know that as we move from left to right in a period atomic size decreases. So lithium has largest size while fluorine has smallest size in second period.
    • Fluorine is most reactive non metal as it requires only one electron to complete its octet and become stable.
    • Lithium is the most reactive metal as it can complete its octet by losing its single electron present in its outermost shell.

PAGE NO : 17
Solution 7:

  1. The most metallic element will be found at C.
  2. The most non-metallic element will be found at D.

Concept Insight: For answering this question you should recall metallic character increases down the group and also increases with the increasing size of the atom. Since elements of group 1 has largest atomic sizes among all the elements of periodic table so the most metallic element belongs to group 1.
Similarly, non-metallic character decreases down the group and increases with the decreasing size of atom.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Periodic Properties and Variation of Properties 1

Solution 9:

  1. 18, 7.
  2. First.
  3. Seventeen.
  4. Electron affinity.
  5. Decrease, increase
  6. Fluorine
  7. Zero.

Solution 10:

  1. False.
  2. True.
  3. True.
  4. True.
  5. True.
  6. True.

Concept Insight: (i) There is inverse relation between atomic size and electron affinity. More is the size, less is the electron affinity and vice versa because more is the size of atom, more is the distance between the nucleus and last shell to which electron enters. This results in decrease in force of attraction between the nucleus and incoming electron and hence the electron affinity decreases. Fluorine has smaller size than chlorine so it must have less electron affinity than chlorine.

Solution 11:

  1. Li < Be < B
  2. I < Br < F < Cl
  3. SiO2 < P2O5 < SO3 < Cl2O7
  4. I+ < I < I–

Concept Insight:

  1. Li, Be, B belongs to second period and ionization energy increase as we move left to right in a period due to increased nuclear charge and decrease of atomic size.
  2. Electron affinity decreases down the group due to increase in atomic size as it results in more distance between nucleus and last shell to which incoming electron enters. Hence, incoming electron feels less attraction from the nucleus.
  3. In a period, acidic nature of oxide increases.
  4. Size of a cation is always smaller than the corresponding atom due to decrease in number of electrons and increase in effective nuclear charge i.e., greater force of attraction by the nucleus on the electrons.
    Size of an anion is always more than the corresponding atom due to decrease in effective nuclear charge i.e., lesser force of attraction by the nucleus o the electrons.

Solution 12:
The statement that in each period, the atomic size gradually decreases with increase in atomic number means that as move from left to right in a period, nuclear charge increases by one unit in each succeeding element while the number of shells remains the same. Due to this increased nuclear charge, the electrons of all the shells are pulled closer to the nucleus thereby bringing the outer most shell closer to the nucleus. With the result, the atomic size decreases across a period.
For example, in the second period from lithium to fluorine, lithium has the largest size while fluorine has the smallest size.

Solution 13:
In the case of noble gases or inert gases there are exceptions and the atomic radius or size of the elements are greater than the other elements of the period to which these elements belong.

PAGE NO : 18
Solution 14:
As we move down a group, the atomic radii increase because a new shell is added at each succeeding element though the number of electrons in the outer most shell remains the same. Thus, the atomic size of elements increases in size downward.
Although nuclear charge also increases in going down the group but the effect of nuclear charge on atomic size is much less than the increase due to addition of a new shell.
In group 17, the atomic size follows the trend:
F < Cl < Br < I

Solution 15:
The elements of third period are:
Na, Mg, Al, Si, P, S, Cl, Ar
The most metallic element is sodium i.e., Na and the most non-metallic element is chlorine i.e., Cl.
Concept Insight:
In a period, metallic character decreases on moving from left to right because of decrease in size of atom due to which elements cannot lose electron easily.

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Periodic Properties and Variation of Properties 2

Solution 17:
Frank ICSE Solutions for Class 10 Chemistry - Periodic Properties and Variation of Properties 3

Solution 18:
Electron affinity is the energy released when an electron is added to an isolated gaseous atom to form the negative ion (anion).
Unit: Its units are electron volt (eV).
Its SI units are Kilojoules per mole(KJmol)-1

Solution 19:
Out of A and B, A will ionize more easily to form a negative anion because of the high value of electron affinity, energy released during addition of electron will be high hence the resulting anion formed will be more stable than the corresponding atom.

Solution 20:

  1. Larger the atomic size, farther is the valence electron from the nucleus and lesser is the pull exerted on it. As a result, electron can be easily removed from the valence shell and hence more metallic is the element.
  2. Halogens need only one electron to complete their octet and become stable their atomic size is very less hence the distance between their last shell and nucleus is very less, as a result the force of attraction between the nucleus and the incoming electron is less and hence the electron affinity is high for halogens.
  3. When an atom loses or gain electron to form ion, the number of electrons present in the outermost shell also changes. Corresponding to that effective nuclear charge on the changed number of electrons also change which further changes the size of an atom as there is inverse relation between effective nuclear charge and size of atom.
  4. K and Li belongs to group 1 i.e., metals and we know that for metals chemical reactivity of elements increases down the group because chemical reactivity increases as electropositive or metallic character increases.
  5. The electronegativity of chlorine is higher than sulphur because both of them belong to third group and chlorine follows sulphur. We know that, within a period electronegativity increases as we move from left to right because of decrease in atomic size and increase in nuclear charge.
  6. Group 17 elements are non metals because they have 7 electrons in their valence shell and ionize by accepting 1 electron to form an anion.
    For example group 17 elements F, Cl, Br and I all have 7 electrons in their valence shell and ionize by accepting 1 electron to form F–, Cl–, Br– and I–.
    Group 1 elements are metals because they have tendency to lose the one electron present in their valence shell and form positive ion.
    For example, group 1 elements Li, Na, K, Rb, Cs have tendency to lose the one electron present in their valence shell and form positive ions Li+., Na+., K+., Rb+.and Cs+.

Solution 21:

  1. (C) i.e. 2, 8, 2 because it has only 2 electrons in its valence shell which can be lost to form a di positive cation.
  2. (C) i.e. 0.72, 0.72
  3. (d) i.e. element forms basic oxide because the element is a metal as it has valency 1.
  4. (a) i.e. F because it belongs to group 17 whose elements have valency 7 and thus requires only 1 electron to complete their octet.

Solution 2000-1:

  1. Number of elements in period 1 = 2
    In period 2 = 8
    In period 3 = 8.
  2. Elements in period 1 are Hydrogen (H) and Helium (He).
  3. Atomic size of elements decreases on moving from left to right in a period.

Solution 2000-2:

  1. The elements at the end of period 2 and period 3 both have their outermost shell complete and belong to noble gases.
  2. An element in group 7 is likely to be non metallic in character since group 7 element will have 7 electrons in its valence shell.
  3. Metallic.

PAGE NO : 19
Solution 2001-1:

  1. Atomic number.
  2. Period, non-metallic.
  3. More.
  4. Number of outer electrons.

Solution 2002-1:
A group is a vertical column of elements having the same number of valence electrons and same valency in the periodic table. There are 18 groups in the periodic table.

Solution 2002-2:
Within a group the element with the greatest metallic character and largest size is expected to be present at the bottom of the group.

Solution 2002-3:
Ionization potential decreases down the group because atomic size increases down the group which decreases the effective nuclear charge over the valence electron which further can now be removed easily.

Solution 2002-4:
There are 8 elements in period 2.

Solution 2003-1:

  1. Al2(SO4)3
  2. Covalent.
  3. The elements of group VIIA all have same number of electrons in their valence shell and same valency.
  4. Neon
  5. 8 electrons are present in the valence shell of the element with atomic number 18.
  6. Electron affinity.
  7. Electronic configuration of element in the third period which gains one electron to become an anion is 2, 8, 7.
  8. Decreases, number of valence shell electrons/outermost shell electrons, valence shell/ outermost shell.

PAGE NO : 20
Solution 2004-1:

  1. Na Mg Al Si P S Cl.
  2. (a) lower, higher.
  3. remains the same.

Solution 2005-1:

  1. b
  2. d
  3. c
  4. a
  5. c

Solution 2006-1:

  1. Second period.
  2. Nitrogen. It should be placed between oxygen andcarbon.
  3. Beryllium < nitrogen < fluorine
  4. Fluorine (F)

Solution 2007-1:

  1. Thallium
  2. Boron
  3. 3
  4. BCl3
  5. The elements in the group to the right of this boron group will be less metallic in character because on moving to the right of the periodic table metallic character decreases as ionization energy deceases and tendency to lose electron also decreases.

Solution 2008-1:

  1. False
  2. True
  3. False
  4. True

Solution 2008-2:

  1. (i) First element in period 2 is Lithium and last element is Neon.
    (ii)Atomic size increases on moving from top to bottom of a group.
    (iii)Chlorine among halogens has the greatest electron affinity.
    (iv) All elements in group 7 have same number of valence shell electrons.
  2. (i) metallic
    (ii) smallest
  3. (i) Ba i.e. Barium will form ion most readily since it is at the bottom of a group its ionization energy is low because its atomic size is more. Due to this effective atomic charge of nucleus over the valence shell electron is least and it can be removed easily.
    (ii) Electro negativity of an element measures the capacity of an element to attract the shared pair of electrons in a bond towards itself.

Solution 2009-1:
(d) Fluorine

PAGE N0 : 22
Solution 2009-2:
Frank ICSE Solutions for Class 10 Chemistry - Periodic Properties and Variation of Properties 4

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