P – BLOCK ELEMENTS – 9

1) UV radiation of sun does not reach the earth because the upper layer of the atmosphere contains
a)
b)
c)
d)

2) The compound of sulphur that can be used as a refrigerant is
a)
b)
c)
d)

3) Arrange the hydrides of chalcogens in the increasing order of ease of formation:
a)
b)
c)
d)

4) The hybridisation of sulphur in H2SO4 is
a) sp
b)
c)
d)

5) Oxygen exhibits a positive oxidation state with
a) F
b) Br
c) Cl
d) I

6) The bond angle in an H2S molecule is
a)
b)
c)
d)

7) All the three atoms of ozone are used up when it reacts with
a) PbS
b)
c) KI
d)

8) 98% H2SO4 is called
a) Pyrosulphuric acid
b) Oleum
c) Both
d) None

9) Yellow ammonium sulphide is
a)
b)
c)
d)

10) Concentrated H2SO4 has great affinity for
a)
b)
c)
d)

11) gas cannot be dried over conc. H2SO4 because
a) The acid oxidises it
b)
c) Both form a complex
d) It dissolves in the acid

12) RRR The anomalous behaviour of oxygen is due to
a) High electronegativity
b) Small atomic size
c) Non availability of d-orbitals
d) All

13) It is possible to obtain oxygen from air by fractional distillation because
a) Oxygen is in a different group of the periodic table from nitrogen
b) Oxygen is more active than nitrogen
c) Oxygen has a higher boiling point than nitrogen
d) Oxygen has lower density than nitrogen

14) Approximately what percentage of air by volume gets used up in a process of combustion ?
a) 20%
b) 10%
c) 35%
d) 55%

15) On exposure to light, the electrical conductivity of selenium
a) Increases
b) Decreases
c) Remains same
d) First decreases then increases

16) The oxide of a non-metal possesses the following characteristics.

(i) It is both a proton donor and proton acceptor

(ii) It is a poor conductor of electricity.

(iii) It reacts readily with basic and acidic oxides

(iv) It oxidises Fe at the boiling point. The oxide is

a)
b)
c)
d) NO

17) The most volatile is
a)
b)
c)
d)

18) The reason why conc. H2SO4 is used largely to prepare other acids is that concentrated H2SO4
a) Is highly ionised
b) Is dehydrating agent
c) Has a high specific gravity and density
d) Has a high boiling point

19) Ammonium persulphate solution on heating under reduced pressure gives
a)
b)
c)
d)

20) The percentage of to be used in rockets is
a) 90%
b) 20%
c) 10%
d) 30%

21) The oxide that gives H2O2 on treatment with dilute acids is
a)
b)
c)
d)

22) Ka for H2O2 is of the order of
a)
b)
c)
d)

23) The amount of H2O2 present in 1 litre of 1.5 N H2O2 solution is
a) 2.5 g
b) 25.5 g
c) 3.0 g
d) 8.0 g

24) The volume of 20 volume H2O2 required to get 5 litres of O2 at STP is
a) 50 mL
b) 250 mL
c) 125 mL
d) 100 mL

25) Which of the following statements is wrong about H2O2 ?
a) It is a good oxidising agent both in acidic and basic medium
b)
c) It is used as antiseptic
d) At normal pressure it is concentrated by using distillation process

26) The mineral from which borax is prepared is
a) Slvyine
b) Colemanite
c) Bauxite
d) Boracite

27) The aqueous solution of borax is
a) Acidic
b) Alkaline
c) Neutral
d) Amphoteric

28) Boric acid is prepared from borax by the
a) Sulphuric acid
b) Sodium hydroxide
c) Carbon dioxide
d) Sodium carbonate

29) is a
a) Base
b) Monobasic acid
c) Dibasic acid
d) Tribasic acid

30) Boron trioxide can be reduced to boron with
a) C
b) Mg
c)
d) Cu

31) Chemically borax is
a) Sodium metaborate
b) Sodium orthoborate
c) Sodium tetraborate
d) Sodium tetraborate decahydrate

32) Which of the following is not a naturally occuring compound of boron ?
a) Colemanite
b) Tincal
c) Kernite
d) Carnallite

33) [email protected] Which is correctly matched ?
a)
b)
c)
d)

34) Boron reacts with NaOH to form
a) Boric acid
b) Borates
c) Boric anhydride
d) None

35) The structure of boric acid is a
a) tetrahedral one
b) trigonal one
c)
d)

36) The least acidic in the series of BF3,BCl3 and BBr3 is BF3 because
a) F is most electronegative
b) F has a small size
c)
d) Back donation of electrons from F to B occurs.

37) Which of the following statements about H3BO3 is not correct ?
a) It is a strong tribasic acid
b) It is prepared by acidifying an aqueous solution of borax.
c)
d) It does not act as a proton donor but as a Lewis acid by accepting hydroxyl ion.

38) The element B is obtained by the reduction of its oxide with a/an
a) Non metal
b) Noble gas
c) Electronegative metal
d) Electropositive metal

39) The banana bond in diborane is constituted by
a) 2 atoms and 2 electrons
b) 2 atoms and 3 electrons
c) 3 atoms and 2 electrons
d) 3 atoms and 3 electrons

40) The state of hybridisation of B in BCl3 is
a) sp
b)
c)
d)

41) RRR In compounds of type ECl3, where E= B,P,As or Bi, the angles of Cl-E-Cl for different E are in the order
a) B > P = As = Bi
b) B > P > As > Bi
c) B < P = As = Bi
d) B < P < As < Bi

42) BCl3 is a planar molecule whereas NCl3 is pyramidal because
a) the B-Cl bond is more planar than the N-Cl bond
b) the N-Cl bond is more covalent than the B-Cl bond
c) Nitrogen is smaller than the boron atom
d)

43) The type of hybridisation of boron in diborane is
a) sp
b)
c)
d)

44) Pick out the electron deficient compound:
a)
b)
c)
d)

45) The shape and hybridisation of BF3 is
a)
b)
c)
d) Planar,sp

46) In the borax bead test of CO2+, the blue colour of bead is due to the formation of
a)
b)
c)
d) CoO

47) Boric acid can be successfully titrated against sodium hydroxide in the presence of
a) Dil.HCl
b) Glycerol
c) Glycine
d) Borax

48) BF3 is
a) Electron deficient
b) a Lewis acid
c) a covalent compound
d) All are correct

49) Which of the following is regarded as a super cooled liquid ?
a) Dry ice
b) Glass
c)
d)

50) The common basic structural unit in silicates and silica is
a)
b)
c)
d)

51) Zeolite which is used for softening of hard water is
a) Hydrated sodium aluminium silicate
b) Sodium calcium silicate
c) Sodium borosilicate
d) Calcium magnesium silicate

52) Which of the following elements react with silicon at room temperature ?
a) Oxygen
b) Chlorine
c) Fluorine
d) Nitrogen

53) Carborundum is the commercial name of
a)
b) SiC
c)
d)

54) Silicon is an important constituent of
a) Chlorophyll
b) Rocks
c) Amalgams
d) Haemoglobin

55) Quartz is a crystalline variety of
a) Si
b)
c) SiC
d)

56) The glass with the smallest coefficient of expansion is
a) Soft glass
b) Flint glass
c) Borosil glass
d) Jena glass

57) The green colour producing substance added to glass is
a)
b) CdS
c)
d)

58) Ultraviolet rays can be checked by
a) Flint glass
b)
c) Soda glass
d) Pyrex glass

59) Optical glasses are made from
a) Sodium glass
b) Flint glass
c) Ground glass
d) Quartz

60) Which of the following shows bonds in silicones ?
a) Si – Si – Si – Si
b) Si – C – Si – O – Si
c) Si – C – Si – C – Si
d) Si – O – Si – O – Si

61) The method used for obtaining highly pure silicon used as a semiconductor material is
a) Oxidation
b) Electrochemical
c) Crystallisation
d) Zone refining

62) In the manufacture of cement which of the following is used ?
a) Clay and silica
b) Limestone and silica
c) Limestone and clay
d) Limestone and gypsum

63) Optical glass contains a high percentage of
a) MgO
b)
c)
d) PbO

64) In the laboratory, silicon can be prepared by the reaction of
a)
b) By heating C in electric furnace
c) By heating potassium flurosilicate with potassium.
d) None of these

65) Crookes glass cuts U.V rays due to the presence of
a)
b)
c) CaO
d)

66) In the manufacture of safety matches, we use
a) White phosphorus
b) Black phosphorus
c) Violet phosphorus
d) Red phosphorus

67) RRR Bones glow in the dark because
a) They contain shining material
b) They contain red phosphorus
c) White phosphorus undergoes slow combustion in contact with air
d) White phosphorus changes into red form

68) One of the acids listed below is formed from and the rest are formed from . The acid formed from phosphorus (III) oxide is
a)
b)
c)
d)

69) Which of the following properties of white phosphorus are shared by red phosphorus ?
a) It phosphoresces in air
b) It reacts with hot aqueous NaOH to give phosphine
c) It dissolves in carbon disulphide
d) It burns when heated in air

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

71) White phosphorus contains
a)
b)
c)
d)

72) The mixture used for the tips of match sticks is
a) S+K
b)
c)
d)

73) Hypophosphorus acid is
a) A tribasic acid
b) A dibasic acid
c) A monobasic acid
d) Not acidic at all

74) If phosphoric acid is allowed to react with sufficient quantity of NaOH , the product obtained is
a)
b)
c)
d)

75) is
a) A tribasic acid
b) A dibasic acid
c) Neutral
d) A monobasic acid

76) Of the following, the most acidic is
a)
b)
c)
d)

77) Superphosphate of lime contains
a)
b)
c)
d)

78) Superphosphate of lime is represented as
a)
b)
c)
d)

79) Which is a constituent of Thomas slag ?
a)
b)
c)
d)

80) Which of the following is the best fertilizer ?
a) Urea
b)
c)
d) CAN

81) Which is the best fertilizer among the following ?
a) Superphosphate
b) Triple phosphate
c) Phosphatic slag
d) None

82) Phosphorus is manufactured by heating in a furnace
a) Bone ash, sodium chloride and coke
b) Bone ash, silica and coke
c) Bone ash, silica and lime
d) Bone ash, coke and lime stone

83) Which one of the following is pyrophosphoric acid ?
a)
b)
c)
d)

84) Phosphine is generally prepared in the laboratory
a) By heating phosphorus in a current of hydrogen
b)
c) By heating white phosphorous with caustic soda
d) By heating white phosphorus with caustic potash

85) The phosphide ion has an electronic structure similar to that of the
a) Nitride ion
b) Fluoride ion
c) Sodium ion
d) Chloride ion

86) Which of the following is a tetrabasic acid ?
a) Orthophosphoric acid
b) Orthophosphorous acid
c) Metaphosphoric acid
d) Pyrophosphoric acid

87) Which is not an acid salt ?
a)
b)
c)
d)

88) When orthophosphoric acid is heated to the product formed is
a)
b)
c)
d)

89) The formula of metaphosphoric acid is
a)
b)
c)
d)

90) Which of the following does not form stable diatomic molecules ?
a) Iodine
b) Phosphorus
c) Nitrogen
d) Oxygen

91) Red phosphorus can be obtained from white phosphorus by
a) Heating it with a catalyst in an inert atmosphere
b) Distilling it in an inert atmosphere
c) Dissolving it in carbon disulphide and crystallizing
d) Melting it and pouring the liquid into water

92) Each of the following is true of white and red phosphorus except that they
a)
b) Can be oxidised by heating in air
c) Consist of same kind of atoms
d) Can be converted to one another

93) When equal weights of the two fertilizers, urea and ammonium sulphate are taken, urea contains
a) Less nitrogen than ammonium sulphate
b) As much nitrogen as ammonium sulphate
c) Twice the amount of nitrogen present in ammonium sulphate
d) More than twice the amount of nitrogen present in ammonium sulphate

94) Which one has the lowest boiling point ?
a)
b)
c)
d)

95) There is very little difference in acid strength in the series , and because
a) Phosphorus in these acids exists in different oxidation states
b) The hydrogen in these acids are not all bound to the phosphorus
c) Phosphorus is not a highly electronegative element
d) Phosphorus oxides are less basic

96) The molecular formula of phosphorus is
a)
b)
c)
d)

97) With reference to protonic acids , which of the following statements is correct ?
a)
b)
c)
d)

98) The P- P- P bond angle in white phosphorus is
a)
b)
c)
d)

99) An oxidation state of +1 for phosphorus is found in
a)
b)
c)
d)

100) forms
a)
b)
c)
d)


Answer

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