P – BLOCK ELEMENTS – 19

1) Of the following statements which are true for NO2 ?

a) A,B
b) A,B,C
c) B,C
d) None

2) H3PO2 is the formula for one of the phosphorus acids. Its name and basicity are respectively.
a) Phosphorus acid and two
b) Hypophosphorus acid and two
c) Hypophosphorus acid and one
d) Hypophosphoric acid and two

3) Bonds present in N2O5 are.
a) Ionic
b) Covalent
c) Covalent and co-ordinate
d) Covalent and ionic

4) Which of the following acids have P-P linkage ?
a) Hypophosphoric acid
b) Pyrophosphoric acid
c) Metaphosphoric acid
d) Orthophosphoric acid

5) The dipole moment of NF3 is less than NH3 because
a) They do not have the same geometry
b)
c) The resultant of the bond polarities is opposed by the polarity of the lone pair
d) The electronegativities of nitrogen and fluorine are quite similar

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

7) Phosphorus vapour has the structure
a)
b)
c)
d)

8) In pyrophosphoric acid the number of hydroxyl groups present are
a) 4
b) 3
c) 5
d) 7

9) RRR There is very little difference in acid strength in the series H3PO4, H3PO3 and H3PO2 because
a) Phosphorus in these acids exists in different oxidation states
b) The hydrogens in these acids are not all bound to the phosphorus
c) Phosphorus is highly electronegative element
d) Phosphorus oxides are less basic

10) Phosphoric acid is syrupy in nature due to
a) Strong covalent bonds
b) Vander Waals forces
c) Hydrogen bonding
d) None

11) Glacial phosphoric acid is
a)
b)
c)
d)

12) White phosphorus may be removed from red phosphorus by
a) Sublimation
b) Distillation
c)
d) All are correct

13) Orthophosphoric acid on heating gives
a) Phosphine
b)
c) Phosphorous acid
d) Metaphosphoric acid

14) At low temperatures NO2 dimerises to N2O4. The dimerisation is accompanied by
a) An increase in pressure
b) A decrease in paramagnetism
c) Darkening in colour
d) Formation of colloid

15) RRR An ammonium compound which is not used as a fertilizer is
a)
b)
c)
d) CAN (calcium ammonium nitrate)

16) The salt which on heating gives a mixture of two gases
a)
b)
c)
d) b and c

17) Which one of the following oxides of nitrogen is paramagnetic ?
a)
b)
c)
d)

18) RRR Sal volatile is
a)
b)
c)
d)

19) RRR Red P is used in making
a) Air freshners
b) Red plastics
c) Red dyes for plastics
d) Safety match-striking surface

20) RRR Conc. HNO3 stains skin yellow because.
a) The proteins are converted into xanthoproteins.
b) The water is removed by the acid
c) The skin is burnt by the acid
d) Nitro cellulose is formed

21) Phosphine is generally prepared in te laboratory
a) By heating phosphorus in a current of hydrogen
b)
c) By heating red P with an aqueous solution of NaOH
d) By heating white P with caustic potash

22) Which of the following sulphides is used in the manufacture of “strike anywhere” matches ?
a)
b)
c)
d) None

23) The product formed when H3PO4 is heated to 600°C is
a)
b)
c)
d)

24) Solid PCl5 exists as
a)
b)
c)
d)

25) The lone pair present on VA group elements in its hydride participates more easily in bond formation in
a)
b)
c)
d)

26) The oxide which shows amphoteric nature is
a)
b)
c)
d)

27) The correct sequence of acidic character is
a)
b)
c)
d)

28) The bonds present in pernitric acid are
a) Ionic bonds
b) Covalent bonds
c) Semi polar bonds or dative bonds
d) Co-ordinate and covalent bonds

29) Red P is prepared from white P by heating it in vacuum to
a)
b)
c)
d)

30) RRR Nitrous acid is slightly blue due to the presence of
a)
b)
c)
d) NO

31) RRR The gas used in Holmes signals is
a)
b)
c)
d)

32) When concentrated HNO3 is heated, it decomposes to give
a)
b) NO
c)
d)

33) Grahams salt is
a) Sodium alumino silicate
b) Sodium hexameta phosphate
c) Ferrous ammonium sulphate
d) Potassium chromium sulphate

34) On heating ammonium dichromate the gas evolved is
a)
b)
c)
d)

35) One mole of calcium phosphide on reaction with excess water gives
a) One mole of phosphide
b) Two moles of phosphoric acid
c) Two moles of phosphine
d) One mole of phosphorus pentoxide

36) RRR In the compound the type ECl3, where E = B, P, As or Bi, the angle Cl-E-Cl for different E are in order.
a) B>P = As = Bi
b) B > P > As > Bi
c) B < P = As + Bi
d) B < P< As < Bi

37) RRR Smelling salt is.
a)
b)
c)
d)

38) PCl5 is prepared by the action of Cl2 on
a)
b)
c)
d)

39) Antimony burns in chlorine to form
a)
b)
c)
d)

40) RRR PCl5 is kept in a well stoppered bottle because.
a) It is volatile
b) It reacts with oxygen
c) It readily reacts with moisture
d) It is explosive

41) Blasting of TNT is done by mixing it with
a)
b)
c)
d)

42) The strongest acid is
a)
b)
c)
d)

43) The arrangement of oxygen atoms around the P atoms in P4O10 is
a) Pyramidal
b) Octahedral
c) Tetrahedral
d) Square planar

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

45) The gas which is a supporter of combustion is
a)
b)
c)
d)

46) One of the following is a good conductor of electricity:
a) Yellow P
b) White P
c) Black P
d) Red P

47) Phosphine is not collected in air because
a) It is poisonous
b) It absorbs moisture
c) It catches fire spontaneously in air
d) It is combustible

48) Sulphuric acid reacts with PCI5 and yields
a) Thionyl chloride
b) Sulphuryl chloride
c) Phosphoric acid
d) Sulphur monochloride

49) The strongest oxidising agent is
a)
b)
c)
d)

50) Calcium ammonium nitrate (CAN) pellets are coated with calcium silicate because
a) CAN is explosive
b) CAN is hygroscopic
c) CAN is water soluble
d) None

51) NaOH can absorb
a)
b) NO
c)
d) All

52) Which sulphide is insoluble in yellow ammonium sulphide ?
a) SnS
b)
c)
d)

53) The catalyst used in the preparation of red P from yellow P is
a)
b) Ni
c) Fe
d) ZnO

54) The hydrolysis of Pl3 yields a
a) Monobasic acid and a salt
b) Monobasic acid and a dibasic acid
c) Dibasic acid and a tribasic acid
d) Monobasic acid and a tribasic acid

55) The number of n bonds in NCl3 is
a) 1
b) 2
c) 3
d) None

56) NCl3 on hydrolysis yields
a)
b) NO, HCl
c)
d)

57) By warming a paste of bleaching powder with a solution of ammonia we get
a)
b)
c)
d)

58) The number of electrons present in the valence shell of P in PCl3 is
a) 8
b) 10
c) 18
d) 12

59) Calcium cyanamide on treatment with steam under pressure gives NH3 and
a)
b)
c)
d) CaO

60) When conc. H2SO4 is added to dry KNO3, brown fumes are evolved. These fumes are of
a)
b)
c)
d)

61) When conc. H2SO4 is distilled with P4O10, the product formed is
a)
b)
c)
d)

62) Nitrous acid reacts with H2SO4 to give
a)
b)
c)
d) None

63) Schweltzers reagent is
a)
b)
c)
d)

64) Conc HNO3 reacts with iodine to form
a) HI
b) HOI
c) HIO3
d)

65) Antimony dissolves in aqua regia to give
a)
b)
c)
d)

66) Nitric acid dissolves sulphur to give
a)
b)
c)
d)

67) Phosphoric acid on reaction with a sufficient amount of NaOH gives
a)
b)
c)
d)

68) The N2O4 molecule is completely changed into a 2NO2 molecule at
a)
b)
c)
d)

69) P4O10 has short and long P-O bonds. The number of short P-O bonds is
a) 4
b) 3
c) 2
d) 1

70) The structure of white phosphorus is
a) Square planar
b) Pyramidal
c) Tetrahedral
d) Trigonal planar

71) Select the correct statement.
a) Sodium metal is stored under kerosene
b) One of the oxides of carbon is a basic oxide
c) Metals can form only basic oxides
d) To prevent combination of white P with oxygen it is kept in kerosene

72) Among the phosphatic fertilizers, super phosphate of lime is a mixture of Ca(H2PO4)2 and
a)
b)
c)
d)

73) In P4O6 the number of oxygen atoms bonded to each P atom is
a) 1.5
b) 2
c) 3
d) 4

74) HNO3 has the following properties.
a) Oxidising and bleaching
b) Acidic and oxidising
c) Basic and reducing
d) Reducing and bleaching

75) Red and yellow phosphorus are
a) Allotropes
b) Isotopes
c) Isobars
d) Isomers

76) P2O5 is used extensively as a
a) Dehydrating agent
b) Catalytic agent
c) Reducing agent
d) Preservative

77) Which acid is not formed by the action of water on P2O5 ?
a)
b)
c)
d)

78) Which of the following is not a drying or dehydrating agent ?
a) Silica gel
b)
c)
d)

79) Nitrogen gas is absorbed by
a) Aluminium carbide
b) Calcium carbide
c) Ferrous sulphate
d) Calcium hydroxide

80) NO and NO2 are
a) Even electron molecules
b) Odd electron molecules
c) Diamagnetic
d) None

81) Nitric acid oxidises phosphorus to
a)
b)
c)
d)

82) Which halide of nitrogen is least basic?
a)
b)
c)
d)

83) The hydrolysis of PCl3 produces
a)
b)
c)
d)

84) Phosphorus pentoxide cannot be used to dry
a)
b)
c)
d)

85) NH4Cl is used to clean metal surfaces because
a)
b)
c)
d) None

86) Calcium super phosphate is
a)
b)
c)
d)

87) RRR Labourers working with phosphorus suffer from a disease in which bones decay. It is called
a) Arthritis
b) Phossy Jaw
c) Rickets
d) Cancer

88) NH3 and PH3 resemble each other in
a) Solubility in water
b) Forming salt with acid
c) Stability
d) Reducing character

89) Which gas can be collected over water?
a)
b)
c)
d) HCl

90) NH3 can be collected by the displacement of
a) Hg
b)
c) NaCl
d)

91) Which of the following are known chalcogens?
a) B, Al, Ga, In
b) N, P, As, Sb
c) F, CI, Br, l
d) O, S, Se, Te.

92) Which one of the following outer electronic configurations represents the elements of group 16 (VIA) or chalcogens ?
a)
b)
c)
d)

93) The electronic configuration of selenium is
a)
b)
c)
d)

94) The atomic number of sulphur is 16. In the ground state of the sulphide ion, the electronic configuration is
a)
b)
c)
d)

95) Which electronic structure is that of an element of group 16 of the periodic table ?
a)
b)
c)
d)

96) The electronic configuration 1s2 2s22p53s1
a) An excited state of fluorine atom
b) The ground state of neon
c)
d)

97) Which of the following sets of atomic numbers belongs to group 16 elements ?
a) 56, 37, 20
b) 52, 8, 84
c) 14, 32, 50
d) 36, 9, 17.

98) The decreasing tendency to exist in puckered 8-membered ring structure is
a) S > Se > Te > Po
b) Se > S > Te > Po
c) S > Te > Se > Po
d) Te > Se > S > Po

99) Which one of the following elements has the highest tendency towards catenation ?
a) Oxygen
b) Selenium
c) Sulphur
d) Tellurium

100) In which of the following pairs is the first atom or the ion not larger than the second ?
a)
b) O, S
c) N, O
d)


Answer

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