P – BLOCK ELEMENTS MCQs- 5

1) A solution containing NH4Cl and NaNO2 on boiling produces
a) Nitrogen peroxide
b) Ammonia
c) Nitrous oxide
d) Nitrogen

2) The stable halide of nitrogen is
a)
b)
c)
d)

3) In NH3 and PH3 the common property is their
a) Odour
b) Combustibility
c) Basic nature
d) None of these

4) Carbon monoxide acts as a Lewis base because it has
a) A double bond between C and O atoms
b) A triple bond between C and 0 atoms
c) A lone pair of electrons on the C atom
d) Two lone pairs of electrons on the 0 atom

5) U.V. rays can be checked by
a) Flint glass
b) Soda glass
c) Pyrex glass
d)

6) Lead pipes can be used safely for carrying
a) Soft water
b) Soft water first treated with lime stone
c)
d) Soft as well as hard water

7) Producer gas is a mixture of
a)
b)
c) CO + water vapours
d)

8) A gas burns with a blue flame and reduces hot copper oxide to copper metal. When burnt in oxygen, It produces a gas which turns lime water milky. The original colourless gas is
a)
b) CO
c)
d)

9) Carbon monoxide is absorbed by
a) Ammoniacal cuprous chloride solution
b) Pyrogallol solution
c) Chloroform
d) Carbon tetrachloride

10) The poisonous gas which combines with the haemoglobin of the blood to form carboxyhaemoglobin is
a) CO
b)
c) HCOOH
d)

11) Dry ice is
a)
b)
c)
d)

12) Which of the following has giant covalent structure ?
a) NaCI
b)
c)
d)

13) Which of the following is used as an oxidising agent in the laboratory ?
a) Lead acetate
b) Basic lead acetate
c) Basic lead carbonate
d) Lead tetraacetate

14) When tin is boiled with alkali solution, the product is
a)
b)
c)
d)

15) Tin reacts with conc. HNO3 to form
a) Metastannic acid
b) Tannic nitrate
c) Stannous nitrate
d) Tin stone

16) Which of the following compounds would you expect to be most ionic in character ?
a)
b)
c)
d)

17) Which of the following statements is not true ?
a) Lead is a true metal with + 2 electrovalency
b)
c)
d)

18) Which of the following statements is not true ?
a)
b)
c)
d)

19) Sandhur used by women is an oxide of lead with the formula
a) PbO
b)
c)
d)

20) White lead is formed when one of the following is added to the solution of any lead salt:

a)
b) Dil HCI
c)
d) Dil. NaOH

21) Which of the following gases, if present in the atmosphere, darkens the surface painted by white lead?
a)
b)
c)
d)

22) Chrome yellow is
a)
b)
c)
d)

23) In silicates, silicon is
a)
b)
c) sp- Hybridized
d)

24) Glass is a homogeneous mixture of
a) Boron and silicon carbides
b) Carbonates of alkali and alkaline earth metals
c) Oxides of alkali and alkaline earth metals
d) Different silicates and borates

25) Lead is most readily dissolved in
a)
b) HCI
c)
d)

26) Water transported through lead pipes becomes poisonous due to the formation of
a) PbO
b)
c)
d)

27) The phenomenon by which activated charcoal removes colouring matter from pure substances is
a) Bleaching
b) Oxidation
c) Reduction
d) Adsorption

28) Which oxidation state is not shown by carbon in its compounds ?
a) -4
b) +4
c) +1
d) 0

29) In which of the following is there a p-d bonding ?
a) Diamond
b) Graphite
c) Dimethylamine
d) Trisilylamine

30) Which of the following is used in making printers ink, shoe polish, black varnish and paint?
a) Bone black
b) Carbon black
c) Gas black
d) Lamp black

31) Which of the following is most electronegative ?
a) Pb
b) Si
c) C
d) Sn

32) A higher percentage of carbon is found in
a) Anthracite
b) Lignite
c) Bituminous
d) Peat

33) The percentage of lead in lead pencils is
a) Zero
b) 20
c) 80
d) 70

34) CCI4 is used as a fire extinguisher because
a) Its m.p. is high
b) It forms covalent bond
c) Its b.p. is low
d) It gives incombustible vapours

35) The correct order of increasing C—O bond length for is
a)
b)
c)
d)

36) The shape of gaseous SnCI2 is
a) Tetrahedral
b) Linear
c) Angular
d) T-shaped

37) The most stable +2 oxidation state is exhibited by
a) Fe
b) Sn
c) Pb
d) Si

38) Mark the oxide which is amphoteric in character:
a)
b)
c)
d) CaO

39) RRR PbF4, PbCI4 exist but PbBr4 and Pbl4 do not exist because of
a)
b)
c)
d)

40) The most stable allotrope of carbon at high temperatures is
a) Diamond
b) Graphite
c) Coal
d) Charcoal

41) The type of hybridization involved in the recently discovered allotrope of carbon (e.g., C60 or fullerene) is
a) sp
b)
c)
d)

42) The correct order of increasing extent of hydrolysis in the following is
a)
b)
c)
d)

43) Which element-element bond has the highest bond energy ?
a) Sn – Sn
b) Ge – Ge
c)
d) Si-Si

44) Dry powder fire extinguisher contains
a) Sand
b)
c) Sand and baking soda
d)

45) Drikold is
a)
b) Ether and dry ice
c) Dry ice and alcohol
d) Dry ice and acetone

46) Carbon is soluble in
a) Conc. HCI
b)
c)
d) Dil. HCI

47) If a person is injured by the shot of a gun and all the pellets could not be removed, it may cause poisoning with
a) Hg
b) Pb
c) Fe
d) As

48) In the sale of diamonds the unit of weight is carat. One carat is equal to
a) 100mg
b) 300mg
c) 400 mg
d) 200 mg

49) Aqua dag is a suspension of ……… in water.
a) Lamp black
b) Charcoal
c) Graphite
d) None.

50) Carbon dioxide is isostructural with
a)
b)
c)
d)

51) CO2 is isostructural with
a)
b)
c)
d)

52) Which of the following are amphoteric ?
a)
b)
c)
d)

53) Which of the following statement(s) is/are true?
a) The lattice structure of diamond and graphite are different
b) Graphite conducts electricity while diamond does not
c) Graphite has lower density than diamond
d) All the above

54) Graphite is
a) a good conductor of heat
b) Softer than diamond
c) Used for making lubricants
d) All the above

55) The reactivity of NO is due to
a) Its low molecular weight
b) Its gaseous state
c) its odd electron
d) None

56) Nitrogen is an essential constituent of all
a) Proteins
b) Fats
c) Proteins and fats
d) None of these

57) Which among the following forms the most basic oxide ?
a) Bi
b) N
c) As
d) P

58) Which phosphorus is used as rat poison ?
a) White
b) Red
c) Scarlet
d) Violet

59) The basicities of the acids H3PO2, H3PO4 and H4P2O7 are respectively
a) 1, 2, 3, 7
b) 2, 3, 4, 7
c) 1, 2, 3, 4
d) 1, 2, 3, 5

60) Red phosphorus is less reactive than yellow phosphorus because
a) It is red in colour
b)
c) It is hard
d) It is highly polymerised

61) Which of the following are fertilizers ?
I. Calcium ammonium nitrate
II. Urea
III Calcium cyanamide
IV. Super phosphate

a) I and II
b) I and III
c) I, II and III
d) All

62) The gas obtained on heating ammonium nitrite is
a)
b)
c)
d)

63) Phosphorus trioxide on reaction with water yields
a) Phosphoric acid
b) Pyrophosphoric acid
c) Phosphorous acid
d) Mixture of phosphorous acid and pyrophosphoric acid

64) The heat of formation of an explosive compound like NCl3 is
a) Positive
b) Negative
c) Zero
d) Positive or negative

65) Which of the following is more acidic ?
a)
b)
c)
d)

66) The structure of PCl5 is
a) Octahedral
b) Trigonal bipyramidal
c) Tetrahedral
d) Pyramidal

67) P4O10 reacts with water to give
a) Hypophosphorus acid
b) Orthophosphorus acid
c) Hypophosphoric acid
d) Orthophosphoric acid

68) Which of the following compounds are not stable ?
a)
b)
c)
d) b and c

69) Which is a basic oxide ?
a)
b)
c)
d)

70) O2, N2 are present in the ratio of 1 : 4 by weight. The ratio of number of molecules is
a) 4 : 1
b) 1 : 4
c) 2 : 1
d) 7 : 32

71) One of the acids given below is formed from P2O3 and the rest are formed from P2O5. The acid formed from P2O3 is
a)
b)
c)
d)

72) Which of the following is not correct ?
a) White and red phosphorus react equally with chlorine at room temperature
b) White phosphorus is metastable, while red phosphorus is stable
c) White phosphorus is lighter than red phosphorus
d) White phosphorus is highly poisonous, while red phosphorus is not

73) PH4I reacts with NaOH to form
a)
b)
c)
d)

74) How is NH3 generally manufactured for fertilizers ?
a)
b)
c)
d)

75) The N-H bond in NH3 is
a) Covalent
b) Ionic
c) Dative
d) Hydrogen

76) Red phosphorus is less reactive, less volatile and soluble specially in non-polar solvents because
a) It has less molecular energy
b) It has high molecular energy
c) It possesses a highly polymerised structure
d) It forms condensation products

77) White P is more reactive than nitrogen because the
a) Electronegativity of P is low
b) lonisation energy of P is low
c)
d)

78) Nitric oxide may be prepared by
a)
b)
c)
d) None

79) Ammonia water makes a good cleaning agent because it
a) Is weakly basic
b) Emulsifies grease
c) Leaves no residue when wiped off
d) All are true

80) The structure of phosphide ion is similar to that of
a)
b)
c) Nitride ion
d)

81) Which of the following is used in the preparation of chlorine ?
a)
b)
c)
d)

82) The acidity of the following acids is in the order
a)
b)
c)
d) None

83) Which does not form interhalogen compounds?
a) F
b) Cl
c) Br
d) All are correct

84) Which is the correct order of basic strength ?
a)
b)
c)
d) None

85) Iodine gives a blue colour with
a)
b)
c) Starch
d)

86) Which of the following is not characteristic of interhalogen compounds ?
a) They are more reactive than halogens
b) They are quite unstable, but none of them is explosive
c) They are covalent in nature
d) They have low boiling points and are highly volatile

87) The bond angle in the chlorine molecule is
a)
b)
c)
d)

88) What is the minimum number of moles of NaOH which would be needed to absorb one mole of Cl2 ?
a) 1
b) 2
c) 3
d) 4

89) Which of the following reacts with H2 in the dark?
a)
b)
c)
d)

90) Which of the following species would you not expect to oxidise?
a)
b)
c)
d)

91) A positive chromyl chloride test is given by a salt containing
a)
b)
c)
d)

92) Which of the following statements is correct?
a) All halogens except fluorine form oxyacids
b) Only chlorine and bromine form oxyacids
c) All halogens form oxyacids
d) Only iodine forms oxyacids

93) Which of the following solutions has the maximum pH ?
a) NaCIO
b)
c)
d)

94) The bond in a molecule of HCl is formed due to the overlapping of
a) s- and p- orbitals
b) s- and sp- orbitals
c) p- and p- orbitals
d) None of these

95) The outer configuration of a halide ion is
a)
b)
c)
d)

96) A gas reacts with CaO, but not with NaHCO3. The gas is
a)
b)
c)
d)

97) A greenish yellow gas reacts with an alkali metal hydroxide to form a halate, which can be used in fire works and safety matches. The gas and halate respectively are
a)
b)
c)
d)

98) The number of p-electrons in a bromine atom is
a) 5
b) 17
c) 15
d) 12

99) The halogen used in the preparation of insecticides is
a)
b)
c)
d)

100) The least bond dissociation energy is possessed by
a)
b)
c)
d)


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