1) Hydrogen combines with other elements by
a) Losing an electron
b) Gaining an electron
c) Sharing an electron
d) All are correct

2) The decomposition of hydrogen peroxide 2H2O2 ® 2H2O + O2 is a
a) Zero order reaction
b) First order reaction
c) Second order reaction
d) Third order reaction

3) Hydrogen will not reduce
a) Heated cupric oxide
b) Heated ferric oxide
c) Heated stannic oxide
d) Heated aluminium oxide

4) One of the most important uses of H2O2 is
a) In dyes
b) In creams
c) In plant nutrition
d) in rocket fuels

5) If an isotope of hydrogen has two neutrons in its atom, its atomic number and atomic mass number will respectively be
a) 2 and 1
b) 3 and 1
c) 1 and 1
d) 1 and 3

6) Decomposition of H2O2 is accompanied by
a) Decrease in free energy
b) Increase in free energy
c) No change in free energy
d) Evolution of heat

7) H2O2 restores the colour of old lead paints, blackened by the action of H2S gas, by

8) Which of the following statements is most appropriate in the case of hydrogen?
a) It can act as a reducing agent only
b) It can act as an oxidising agent only
c) It can act as both oxidising and reducing agent
d) It can neither act as an oxidising nor as a reducing agent

9) Strength of 2N H2O2 solution is approximately
a) 10 volumes
b) 11.2 volumes
c) 22.4 volumes
d) 1.12 Volumes

10) The action of steam on heated iron is represented as

11) Industrial hydrogen is prepared by passing an electric current through a solution of
a) NaOH

12) Which of the following statements is wrong?
a) Ordinary hydrogen is an equilibrium mixture of ortho and para hydrogen
b) In ortho hydrogen, the spin of the two nuclei is in the same direction
c) Ortho and para forms do not resemble each other in their chemical properties
d) In para hydrogen, the spin of the two nuclei is in opposite directions

13) The ionisation energy of hydrogen is
a) Equal to that of chlorine
b) Smaller than that of chlorine
c) Slightly higher than that of chlorine
d) Much higher than that of chlorine

14) The number of moles of H2 in 0.224 litre of Hydrogen gas at STP (273K 1 atm.) is
a) 1
b) 0.1
c) 0.01
d) 0.001

15) H2O has a higher boiling point than H2S because

16) Hydrogen cannot be obtained by

17) Pure nascent hydrogen is best obtained by
c) Al and NaOH
d) All of these

18) Which of the following halogens has maximum affinity for hydrogen?

19) Hydrogen acts as an oxidising agent in

20) A 10 volume solution of H2O2 means

21) An oxide that gives H2O2 on treatment with dilute H2SO4 is

22) The radius of a hydrogen atom in the ground state is . The radius of a Li2+ ion (atomic number = 3) in a similar state is

23) Decomposition of H2O2 is accelerated by
a) Traces of acids
b) Finely divided metals
c) Acetanilide
d) Alcohol

24) Calculate the normality of 10 volume H2O2
a) 0.178 (N)
b) 12 (N)
c) 30.3 (N)
d) 0.0303 (N)

25) The last molecule of H2O is evolved from H2O2 by
a) Crystallisation
b) Evaporation
c) Distillation under reduced pressure
d) Electrolysis

26) Which of the following statements is not correct for hydrogen?
a) Its molecule is diatomic
c) It resembles alkali metals and halogens in its properties
d) Heavy water is unstable because hydrogen is substituted by its isotope deuterium

27) Hard water does not give good lather with soap, because soap is precipitated as
a) Magnesium and calcium stearates
b) Calcium and magnesium carbonates
c) Hydroxides of calcium and magnesium
d) None is correct

28) Crystals of washing soda lose nine molecules of water when exposed to dry air. This phenomenon is known as
a) Dehydration
b) Deliquescence
c) Efflorescence
d) Evaporation

29) On an industrial scale, hydrogen peroxide is now generally prepared by
d) Burning hydrogen in excess of oxygen

30) Hydrogen peroxide cannot be concentrated easily because
a) It is highly volatile in nature
b) It is not miscible with water
c) It decomposes at its boiling point
d) It has a very high boiling point

31) The H— O— O bond angle in H2O2 is

32) The correct increasing order of acidity of CO2, H2O and H2O2 is

33) In which of the following equations does H2O2 act as a reducing agent in acidic medium?

34) In acidic medium, H2O2 acts as a reducing agent in its reaction with

35) In basic medium, H2O2 acts as an oxidising agent in its reactions with

36) The decomposition of H202 can be checked by the addition of
a) Akali metal oxides
b) Benzene
c) Acetanilide

37) Which of the following reactions depicts the reducing action of H2O2?

38) Which one of the following reactions demonstrates that H2O2 acts as an oxidising agent in the basic medium?

39) When hydrogen peroxide is treated with a cold acidified K2Cr2O7 solution containing ether, a blue colour is obtained. This is due to
a) Chromium sulphate
b) Potassium chromate
c) Perchromic acid
d) Chromium trioxide

40) What would happen when a small quantity of H2O2 is added to a solution of FeSO4?

41) 100 cm3 of a given sample of H2O2 gives 1000 cm3 of O2 at S.T. P. The given sample is

42) A dilute solution of H2O2 is labelled as 20 volume. Its percentage strength is

43) The normality of 30 volume H2O2 solution is
a) 3.57
b) 7. 53
c) 5.36
d) 5. 73

44) A sample of H2O2 is labelled as 10 volume. Its strength in gram/litre is
a) 30.35
b) 60.7
c) 15.17
d) 45.42

45) Which of the following compounds turns white on treatment with H2O2?
a) HgS
b) PbS
c) NiS
d) CuS

46) The reaction Ag2O + H2O2 ® 2 Ag + H20 + O2 takes place in
a) Basic medium
b) Acidic medium
c) Neutral medium
d) Both acidic and basic medium

47) H2O2 is used as
a) Antiseptic
b) Bleaching agent
c) Propellent
d) All

48) One of the following is an incorrect statement, point it out.
a) Permanent hardness can be removed by boiling water
b) Hardness of water affects soap consumption
c) Temporary hardness is due to bicarbonates of Ca and Mg

49) Heavy water is called heavy because it
a) Is denser than common water
b) Is an oxide of deuterium
c) Has a heavy or bad taste
d) Has a heavier isotope of oxygen

50) The melting point of most solid substances increases with an increase of pressure acting on them. However, ice melts at a temperature lower than its usual melting point when the pressure is increased. This is because
a) Pressure generates heat
b) The chemical bonds break under pressure
c) Ice is less denser than water
d) Ice is not a true solid

51) Water boils and freezes exactly at 100°C and 0°C respectively; find the reason for it from the following
a) Water dissolves anything however sparingly the dissolution may be
b) Water is a polar molecule
c) The boiling and freezing temperatures of water were used to define temperature scales
d) Liquid water is denser than ice

52) A variety of water which contains soluble salts of Ca and Mg is known as
a) Heavy water
b) Soft water
c) Hard water
d) Conductivity water

53) To test whether a given clear liquid is water; of the following methods, the best one could be
a) Smell the liquids
b) Add anhydrous copper sulphate and look for a colour change
c) Taste the liquid
d) Moisten litmus paper with the solution

54) The oxide that gives H2O2 on treatment with dilute acid is

55) Hydrogen peroxide is used as
a) A bleaching agent
b) An oxidising agent
c) An oxidant in rocket fuel
d) All of the above

56) RRR On an industrial scale, H2O2 is now generally prepared by

57) Heavy water is
b) Water obtained by repeated distillation

58) The reaction H2S +H2O2 S+2H2O manifests the

59) The reaction of H2O2 with sulphur is an example of a/an ….. reaction
a) Addition
b) Oxidation
c) Reduction
d) Acidic

60) H2O2 acts as an oxidising agent in
a) Neutral medium
b) Acidic medium
c) Alkaline medium
d) Acidic as well as alkaline medium

61) Which of the following statements is incorrect ?

62) H2O22H++O2 + 2e- ; E° =-0.68 V. The above equation represents which of the following properties of H2O2 ?
a) Reducing
b) Oxidising
c) Acidic
d) Cataiytic

63) Which one of the following removes temporary hardness of water?
a) Slaked lime
b) Plaster of Paris
c) Epsom
d) Hydrolith

64) Heavy water is used in nuclear reactors for
a) being the
b) Slowing down the speed of high energy neutrons
c) Transporting heat from the reactor
d) Heating purposes

65) When sulphur trioxide is heated with heavy water the products are
a) Deutero-sulphuric acid
b) Deuterium sulphuric acid
c) Deuterium and sulphuric acid
d) None of the above

66) Of the following which one is a true peroxide?
a) PbO
d) CaO

67) A dilute solution of H2O2 cannot be concentrated by
a) Vacuum distillation
c) Fractional crystallization at lower temperature
d) Careful and slow evaporation in a shallow dish

68) D2O will have maximum density at
a) 9 degree Celsius
b) 11.5 degree Celsius
c) 15.9 degree Celsius
d) 20 degree Celsius

69) The hair dyes available in the market generally contain two bottles, one containing dye and the other hydrogen peroxide. Before applying the dye, the two solutions are mixed. The hydrogen peroxide
a) Is added to dilute the solution of the dye
b) Oxidises the dye to give the desired colour
c) Reduces the dye to give the desired colour
d) Acidifies the solution of the dye

70) Which of the following statements is not correct?

71) Moist hydrogen peroxide cannot be dried over conc. H2SO4 because
a) It can catch fire

72) Decomposition of H2O2 is favoured by
a) Traces of acids
b) Alcohol
c) Acetanilide
d) MnO

73) The maximum possible number of hydrogen bonds a water molecule can form in ice is
a) 1
b) 2
c) 3
d) 4

74) Which pair of ions causes hardness of water?

75) An inorganic substance liberates O2 when heated, turns an acid solution of Kl brown and reduces acidified KMnO4. The substance is

76) 30 volumes of H2O2 means

77) 11.2 volumes of H2O2 is about
a) 3.4%
b) 0.34%
c) 34%
d) 0-34%

78) One of the following is an incorrect statement. Point out the incorrect one
a) Hardness of water depends upon its soap consuming power
b) Temporary hardness is due to the presence of bicarbonates of calcium and magnesium
c) Permanent hardness is caused by soluble sulphates and chlorides of Ca and Mg
d) Permanent hardness can be removed by boiling water

79) In aqueous solution hydrogen peroxide oxidises H2S to
a) Sulphur
b) Sulphuric acid

80) Which of the following groups of ions makes water hard?
a) Sodium and bicarbonate
b) Magnesium and chloride
c) Potassium and sulphate
d) Ammonium and chloride

81) The correct order of the O—O bond length in O2, H2O2 and O3 is

82) Commercial 10 volume H2 O2 is a solution with a strength of approximately
a) 30%
b) 3%
c) 1%
d) 10%

83) The hydride ion H is a stronger base than its hydroxide ion OH. Which of the following reactions will occur if sodium hydride (NaH) is dissolved in water?
d) None of these

84) What is heavy water?

85) The low density of ice compared to water is due to
a) Hydrogen bonding interactions
b) Dipole—dipole interactions
c) Dipole—induced dipole interactions
d) Induced dipole—induced dipole interactions

86) Which among the following has the largest dipole moment?
a) HI

87) The alum used for purifying water is
a) Ferric alum
b) Chrome alum
c) Potash alum
d) Ammonium alum

88) Which of the following metals will not reduce H2O?
a) Ca
b) Fe
c) Cu
d) Li

89) The reaction of potassium with water is
a) Exothermic
b) Endothermic
c) Hydrolysis
d) Absorption

90) Amongst H2O, H2S, H2Se and H2Te, the one with the highest boiling point is

91) A metal X on heating in nitrogen gas gives Y. Y on treatment with H2O gives a colourless gas which when passed through CuSO4 solution gives a blue colour. Y is
d) MgO

92) The volume strength of perhydrol is
a) 20
b) 30
c) 100
d) 10

93) Water shows which type of properties?
a) Acidic
b) Basic
c) Oxidising
d) All the above

94) Organic ion exchangers can produce
a) Soft water
b) Deionised water
c) Demineralised water
d) Both (b) and (c)

95) H202 can be prepared by
d) All the above

96) In an aqueous solution hydrogen will not reduce
a) Fe3+

b) Cu2+

c) Zn2+

d) Ag+

97) H2O2 restores the colour of old lead paintings by

a) Oxidizing PbS to PbSO4

b) Reducing PbS to Pb

c) Forming a complex

d) None of these

98) Hydrazoic acid is
a) H2 N2

b) HNO4

c) NH3

d) N3 H

99) The normal pH in the stomach is about
a) 7
b) 5
c) 2
d) -2


Ans 1) d

Ans Desc 1) Hydrogen is electropositive and easily gives .

Ans 2) b

Ans Desc 2) H2O2 ® H2O + O. It is a first order reaction.

Ans 3) d

Ans Desc 3) Al is more electropositive than H. Fe and Sn are also more electropositive than H, but they are reduced by H2. Fe3+ to Fe2+ and Sn4+ to Sn2+.

Ans 4) d

Ans Desc 4) H202 is used as an oxidant in rocket fuels with hydrazine (N2H4).

Ans 5) d

Ans Desc 5) No. of neutrons in = 3 -1 = 2

Ans 6) a

Ans Desc 6) Decomposition of H2O2 is spontaneous process. Thus G = -ve.

Ans 7) b

Ans Desc 7)

Ans 8) c

Ans Desc 8) Hydrogen can lose one electron to form H+ (oxidation) and it can also gain an electron to form ion (reduction).

Ans 9) b

Ans Desc 9) Normality of 10 vol. H2O2 = 1.78. Thus Volume strength of 1.78 N solution is 10. Hence volume strength of 2 N H2O2 = 2 x 10/ 1.78= 11.2.

Ans 10) a

Ans Desc 10)

Ans 11) a

Ans Desc 11) By electrolysis of NaOH.

Ans 12) c

Ans Desc 12) Ortho and para hydrogen have similar chemical properties because they have the same atomic number.

Ans 13) c

Ans Desc 13) IE of chlorine is 1255 kJ/mole and IE of hydrogen is 1312 kJ/mole.

Ans 14) c

Ans Desc 14) 22.4 litres are present in 1 mole of H2.

Thus 0.224 litre would be present in 1 x 0.224/22.4 = 0.01 mole.

Ans 15) c

Ans Desc 15) The b.p of H2O is higher than that of H2S because of intermolecular hydrogen bonding in liquid H2O.

Ans 16) b

Ans Desc 16) 4Zn+ 10HNO3® 4Zn(NO3)2 + 2NH4NO3 + 3H2O.

Ans 17) d

Ans Desc 17) Nascent hydrogen can be prepared by all these methods.

Ans 18) a

Ans Desc 18) Decreasing order of reactivity of halogens towards hydrogen is F2 > Cl2 > Br2 > I2.

Ans 19) b

Ans Desc 19) In the reaction K + H ® KH, hydrogen is acting as an oxidising agent.

Ans 20) d

Ans Desc 20) 10 volume solution means 1ml of that sample of give 10ml of at STP.

Ans 21) b

Ans Desc 21) Na2O2+ H2SO4® Na2SO4 + H2O2

Ans 22) c

Ans Desc 22) Radius of Li+ = 0.53/3 = 0.17 A0

Ans 23) b

Ans Desc 23)

Ans 24) a

Ans Desc 24) A 10 vol. H2O2 solution is roughly of 3% strength. 1 mL of 10 volume H2O2 will liberate 10 mL of O2 at STP. Now 68 g. of H2O2 liberates 22400 mL of O2 at STP. Thus weight of 1. mL of O2 at STP = 68 x 10/22400 = 0.03 g. Strength of 10 volume H2O2 = 3.03 g./litre. Now normality x Eq. wt. = 3.03 or Normality = 3.03/17 = 0.178.

Ans 25) a

Ans Desc 25) Nil

Ans 26) d

Ans Desc 26) Heavy water is a stable compound.

Ans 27) a

Ans Desc 27) Nil

Ans 28) c

Ans Desc 28) Efflorescent substances lose their moisture or water of crystallisation.

Ans 29) c

Ans Desc 29)

At anode: ® H2S2O8 +2 e

H2S2O8 + H2O ® H2SO5 + H2SO4;

H2SO5 + H2O ® H2SO4 + H2O2.

Ans 30) c

Ans Desc 30)

Ans 31) a

Ans Desc 31)

Ans 32) b

Ans Desc 32) CO2 is a stronger acid than H2O2 since it liberates H2O2 from BaO2. Water, of course, is a weaker acid than H2O2.

Ans 33) c

Ans Desc 33) H2O2 ® 2 H+ + O2 + 2 erepresents reducing action of H2O2.

Ans 34) b

Ans Desc 34)  + 6 H+ + 5 H2O2 ® 2 Mn2+ + 8 H2O+5 O2

or 2 KMnO4 + 3 H2SO4 + 5 H2O2 ® K2SO4 + 2 MnSO4 + 8 H2O + 5 02.

Ans 35) a

Ans Desc 35) Cr2 (S04)3 + 3 H2O2 + 10 NaOH® 2 Na2CrO4 + 3 Na2SO4 + 8 H2O

or 2 Cr3+ + 3 H2O® 10 OH®

Ans 36) c

Ans Desc 36) Acetanilide prevents the decomposition of H2O2.

Ans 37) c

Ans Desc 37)  + 6 H+ + 5 H2O2 ® 2 Mn2+ + 8 H2O+ 5O2

or 2 KMnO4 + 3 H2SO4 + 5 H2O2 ® K2SO4 + 2 MnSO4 + 8 H2O + 5O2.

Ans 38) a

Ans Desc 38) Here Mn2+ is oxidised to MnO2 in a basic medium by H2O2.

Ans 39) c

Ans Desc 39) K2Cr2O7 + H2SO4 + 4 H2O2® K2SO4 + 2 CrO5+5H20

CrO5 is the peroxide of Cr which dissolves in ether producing a blue colour.

Ans 40) d

Ans Desc 40) 2 Fe2+ + H2O2 + 2 H+ ® 2 Fe3+ + 2 H2O

or Fe2+® Fe3+ +.

Ans 41) c

Ans Desc 41) 2H2O2 ® 2H2O +O2

100ml           1000ml

or 1 ml of H2O2 will give 10 ml of O2 at STP.

Thus its volume strength is 10 volume.

Ans 42) b

Ans Desc 42) From the formula vol.strength = Normality x 5.6, find normality.
Then strength (g//)= normality x 17 (eq.wt.) % amount can be calculated

Ans 43) c

Ans Desc 43)

Ans 44) a

Ans Desc 44) 

Thus strength (g/l)=

Ans 45) b

Ans Desc 45) PbS +4 H2O2 ® PbSO4 +4 H2O

Black                  White

Ans 46) a

Ans Desc 46) H2O2 on oxidation gives O2 only in basic medium.

Ans 47) d

Ans Desc 47) All three are uses of H2O2

Ans 48) a

Ans Desc 48)

Ans 49) b

Ans Desc 49) Deuterium() is called heavy hydrogen, therefore is heavy water.

Ans 50) c

Ans Desc 50) On increasing pressure, the coordination number of ions in solids usually increases, thereby increasing their m.p. but in ice, pressure does not increase the C.N. of oxygen and thus the m.p. does not increase but decreases under pressure.

Ans 51) c

Ans Desc 51) Nil

Ans 52) c

Ans Desc 52) Hardness of water is due to Ca and Mg chlorides and sulphates.

Ans 53) b

Ans Desc 53) Anhydrous CuS04 (white) changes its colour to blue in contact with water.

CuSO4 + 5 H2O ® CuSO4.5 H2O (blue)

Ans 54) b

Ans Desc 54) Na2O2 + H2SO4 Na2SO4 +H2O2

Ans 55) d

Ans Desc 55)

Ans 56) c

Ans Desc 56)

At anode: ® H2S2O8 +2 e

H2S2O8 + H2O ® H2SO5 + H2SO4;

H2SO5 + H2O ® H2SO4 + H2O2.

Ans 57) c

Ans Desc 57)

Ans 58) c

Ans Desc 58) H2S is oxidised to S by H2O2.

Ans 59) b

Ans Desc 59) is oxidised to sulphur by .

Ans 60) d

Ans Desc 60) Nil

Ans 61) d

Ans Desc 61) H2O2 does not have basic properties.

Ans 62) a

Ans Desc 62) The equation represents the reducing behaviour of H2O2.

Ans 63) a

Ans Desc 63) Ca(OH)+Ca(HCO3)2 ® +2 H2O.

Ans 64) b

Ans Desc 64) Heavy water is used as a moderator in nuclear reactors to slow down the speed of fast moving, (high energy) neutrons.

Ans 65) a

Ans Desc 65) SO3 + D2O D2SO4 (Deutero sulphuric acid)

Ans 66) c

Ans Desc 66) BaO2 + H2SO4 BaSO4 + H2O2 ; others are simple oxides.

Ans 67) b

Ans Desc 67) P2O5 is a drying agent used to remove small amounts of

moisture. It cannot be used for concentration of H2O2 solution.

Ans 68) b

Ans Desc 68)

Ans 69) b

Ans Desc 69)

Ans 70) d

Ans Desc 70) H2O2 is not a weak base but a weak acid.

Ans 71) c

Ans Desc 71) + [ O ] H2O +
From H2S04

Ans 72) d

Ans Desc 72) MnO catalyses the decomposition of H2O2.

Ans 73) d

Ans Desc 73) In ice, each H20 molecule is surrounded by four other water molecules, bonded through H-bonds.

Ans 74) c

Ans Desc 74)

Ans 75) b

Ans Desc 75) 2 H2 O2 2 H2O +O2

KI +H2SO4 +H2 O2 K 2SO4 +I2 +2 H2O


+3 H2SO4 + 5 H2 O2 + + 8 H2O + 5 O2.

Ans 76) c

Ans Desc 76)

Ans 77) a

Ans Desc 77) 11.2 = Normality x 5.6;

Ans 78) d

Ans Desc 78)

Ans 79) a

Ans Desc 79) H2S +H2O2 2 H2O +S

Ans 80) b

Ans Desc 80) Mg2+ and Cl ions make water hard.

Ans 81) c

Ans Desc 81) In H2O2, there is a single bond between O—O, in O3 there is a resonance between a single and a double bond and in O2 there is a double bond.

Therefore the O—O bond length decreases in the order H2O2 > O3 > O2

148 pm 128 pm 121 pm

Ans 82) b

Ans Desc 82) 

10 volume H2O2 has normality = 1 .7 .

Therefore strength (gr//)= 1.7 x 17 and % strength =

Ans 83) b

Ans Desc 83) H will take up H+ from H2O to give H2.

Ans 84) d

Ans Desc 84) Deuterium is heavier than hydrogen hence heavy water is D2O.

Ans 85) a

Ans Desc 85) Low density of ice compared to water is due to H-bonding interactions which leave large empty spaces in the crystal lattice.

Ans 86) b

Ans Desc 86) H2O due to the presence of two lone pairs on O atom has the maximum value of dipole moment 1.84 D.

Ans 87) c

Ans Desc 87) Potash alum contains AI3+ ions which coagulate the dust particles, which then settle down.

Ans 88) c

Ans Desc 88) Cu is less electropositive than hydrogen.

Ans 89) a

Ans Desc 89) K reacts with H2O liberating H2 and heat.

Ans 90) a

Ans Desc 90) H2O has the highest b.p. Due to H- bonding in it, more heat is required to vapourise it.

Ans 91) b

Ans Desc 91) Metal X is Mg.

3 Mg + N2 Mg3N2
Thus Y is Mg3N2

Mg3 N2 +6 H2O [Cu(NH3)4]SO4(colourless gas)

(Blue coloured solution)

Ans 92) c

Ans Desc 92) Perhydrol is 30% H2O2.

10 vol. H2O2 = 3% then 30% H2O2 has 100 volume strength.

Ans 93) d

Ans Desc 93)

Ans 94) d

Ans Desc 94)

Ans 95) d

Ans Desc 95) H202 can be prepared by all the three methods mentioned above.

Ans 96) c

Ans Desc 96)

Ans 97) a

Ans Desc 97)

Ans 98) d

Ans Desc 98)

Ans 99) c

Ans Desc 99) The pH in the stomach is 2 which is in the acidic range

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