P – BLOCK ELEMENTS – 6

1) Which of the following oxyacids of chlorine is least oxidising in nature?
a) HOCl
b)
c)
d)

2) The melting point of halogens decreases in the order
a)
b)
c)
d)

3) The bleaching solution used for bleaching cloth and paper contains
a)
b)
c)
d)

4) The increasing order of reducing power of the halogen acid is
a) HF < HCl < HBr < HI
b) HI < HBr < HCl < HF
c) HBr < HCl < HF < HI
d) None is correct

5) The low bond energy of the fluorine molecule is best explained by
a) The high electronegativity of fluorine
b) The small size of fluorine
c) The attainment of noble gas configuration by fluorine
d) Repulsion by lone pairs of fluorine

6) Fluorine is a strong oxidising agent. This can be explained by many factors, except its
a) Heat of dissociation
b) Reduction potential
c) lonisation potential
d) Heat of hydration

7) 0.12 g of a substance when burnt in oxygen yields 0.44 gram of its oxide. The substance is
a) Sulphur
b) Carbon
c) Nitrogen
d) Sodium

8) Which element of V group gives the most basic compounds with hydrogen?
a) N
b) Bi
c) As
d) P

9) The sulphate of a metal has the formula M2(SO4)3. The formula for its phosphate will be
a)
b)
c)
d)

10) Which of the following has a layer structure ?
a) Black P
b) White P
c) Red P
d) Yellow P

11) NO2 can be obtained by heating
a)
b)
c)
d)

12) A white turbidity is obtained when one of the following reacts with water:
a)
b)
c) NaCl
d)

13) From which of the following reactions is phosphine not obtained?
a) White P + NaOH
b) Red P+ NaOH
c) Yellow P + NaOH
d) All of these

14) Which forms a new compound in air?
a)
b)
c) P in air
d)

15) The oxide of nitrogen which is readily soluble in alcohol is
a)
b)
c)
d) NO

16) Nitrolim is
a)
b)
c)
d)

17) When iron is brought in contact with conc.HNO3
a) It reacts immediately
b) It reacts very slowly
c) It becomes passive
d) It gives ferrous nitrate

18) Which of the following is a correct statement?
a)
b) Nitric oxide is diamagnetic
c) Nitric oxide is an endothermic compound
d) Nitric oxide gas is used to induce general anaesthesia

19) In the action of HNO3 on metals, the evolution of NO2 is favoured by
a)
b)
c)
d)

20) The acid of phosphorus which coagulates egg albumin is
a)
b)
c)
d)

21) PH3 gas is
a) Acidic
b) Basic
c) Neutral
d) Amphoteric

22) 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 into one another

23) Ammonium nitrite is not used for the laboratory preparation of nitrogen because it is
a) Very explosive
b) Explosive
c) Not easily available in the pure state
d) None

24) Which of the following reagents can separate nitric oxide from nitrous oxide?
a) Sodium nitroprusside solution
b)
c)
d) Ammonical silver nitrate solution

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

26) A black sulphide when treated with ozone becomes white. The white compound is
a)
b)
c)
d)

27) The aqueous solution of ammonia contains
a)
b)
c)
d)

28) Bones glow in the dark. This is due to the
a) presence of red phosphorus
b) Conversion of white P into red P
c) Slow combustion of white P in contact with air
d) Conversion of red P into white P

29) Which one of the following formulae does not represent a salt derived from phosphoric acid,H3PO4?
a)
b)
c)
d)

30) A compound which leaves behind no residue on heating is
a)
b)
c)
d) None of these

31) Which of the following when heated gives off a gas or mixture of gases which cannot relight a glowing splinter?
a)
b)
c)
d)

32) The gas used in the manufacture of ice cream is
a)
b)
c) NO
d)

33) Which phosphorus causes Phossy Jaw?
a) White
b) Red
c) Scarlet
d) Violet

34) Phosphorus is present in the bones in the form of
a) Calcium sulphate
b) Calcium phosphate
c)
d) Calcium fluoride

35) Which is correct about white phosphorus?
a)
b) It is violet red solid
c) It is not poisonous
d)

36) The gas not having oxidising and bleaching properties is
a) Chlorine
b) Ozone
c) Sulphur dioxide
d) Nitrous oxide

37) Which of the following configurations is characteristic of group 13 (Group III A) elements ?
a)
b)
c)
d)

38) An element with atomic number 31 belongs to the

a) s-Block
b) p-Block
c) d-Block
d) f-Block

39) Which of the following set of atomic numbers belongs to Group 13 elements ?
a) 3,11,19
b) 2, 10,18
c) 31,13,49
d) 7, 17, 31

40) The electronic configuration of gallium is
a)
b)
c)
d)

41) Which of the following electronic configuration would you expect to have the lowest ionization energy ?
a)
b)
c)
d)

42) The first ionization potential of aluminium is smaller than that of magnesium because
a)
b)
c) Al has one electron in the p-orbital
d)

43) The first ionization energy of B is less than that of Be because
a) Boron has a higher nuclear charge
b) the atomic size of B is more than that of Be
c) the atomic size of B is less than that of Be
d) B has one electron in the p-orbital

44) The monovalency of the heavier members of group 13 elements can be explained on the basis of
a) Their low ionization energies
b) Their low electronegativity values
c) Their large sizes
d) the inert pair effect

45) Group 13 elements exhibit
a)
b)
c)
d)

46) Which of the following is most abundant among group 13 elements in the earths crust ?
a) B
b) Al
c) Ga
d) None of these

47) The elements which react with air more readily are
a) Al
b) B
c) Ga
d) All the above

48) Generally the atomic and ionic radii increase with increase in atomic number down the group. But the atomic size of aluminium and gallium is almost the same. This is because
a) The nuclear charge of Ga is higher than that of Al
b) Gallium contains intervening d-electrons which do not screen the valence electrons effectively
c) The ionization energies of Ga and Al are comparable
d) All the three above

49) The anomalous behaviour of nitrogen is due to its
a) Small size and high electronegativity
b) Non-availability of d-orbitals in valence shell
c) Ease of multiple bond formation
d) All are correct

50) When heated to 800°C, N2O gives
a)
b)
c)
d) None

51) Which of the following is not in the correct order ?
a)
b)
c)
d) All are correct

52) Metalic nitrides on hydrolysis with water give
a)
b)
c) NO
d)

53) Which of the nitrogen oxides is a white solid ?
a)
b)
c)
d)

54) Which of the following is false ?
a)
b)
c)
d)

55) In the atmosphere N2 is present as an element with O2 because
a)
b)
c)
d)

56) Pearl white is
a) BiOCl
b) SbOCl
c) NOCl
d) AsOCl

57) Aqua fortis is
a)
b)
c)
d)

58) Which of the following is most stable ?
a)
b)
c)
d)

59) With an excess of Cl2, ammonia gives
a)
b) HCl
c)
d)

60) Sodium nitrate on heating with Zn dust and caustic soda gives
a)
b)
c)
d)

61) A man may die when he inhales nitrous oxide in a large quantity because
a) It is poisonous
b) It causes laughing hysteria
c) It deactivates haemoglobin
d) None

62) The yellow colour of usual HNO3 is due to the presence of
a)
b)
c)
d)

63) In the catalytic oxidation of NH3 an oxide is formed which is used in the manufacture of HNO3.The oxide is
a)
b)
c)
d)

64) A substance that has a low kindling point and is stored under water is
a) P
b) S
c) Na
d) C

65) Which of the following shows chemiluminescence ?
a) White P
b) Black P
c) Red P
d) None

66) RRR Mixture used for the tips of match stick is
a) S + K
b)
c)
d)

67) RRR The composition of safety match head is.
a)
b)
c)
d) None of these

68) Which of the following has the maximum complex forming ability with a given metal ion ?
a)
b)
c)
d)

69) At high temperature nitrogen combines with CaC2 to form
a) CaCN
b)
c)
d)

70) Hyponitrous acid is
a) HNO3
b)
c)
d) None

71) Which of the following forms of phosphorus is most stable ?
a) Red P
b) White P
c) Black P
d) All are stable

72) The oxyacid of phosphorus that can reduce AgNO3 to Ag is
a)
b)
c)
d)

73) HPO3 + H2O
a)
b)
c)
d)

74) Which of the following has the minimum boiling point ?
a)
b)
c)
d)

75) The high heat of vapourisation of NH3 is due to
a) Its basic nature
b) Its polar nature
c) Hydrogen bonding
d) its solubility in water

76) A compound of phosphorus used as a drying agent and desiccating agent is
a)
b)
c)
d)

77) Nitric oxide has Â…. valence electrons
a) 10
b) 13
c) 11
d) 12

78) The acid used in soft drinks is
a)
b)
c)
d)

79) Of the following statements, which are true for NO2. (A) NO2, brown liquid, turns paler on cooling, also becomes a colourless solid (B) NO2 undergoes dimerisation to form N2O4 (C) NO2 is paramagnetic but N2O4 is diamagnetic
a) A, B
b) A, B, C
c) B, C
d) None

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

81) The bonds present in N2O5 are
a) Ionic
b) Covalent
c) Covalent and co-ordinate
d) Covalent and ionic

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

83) 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 electronegativity of nitrogen and fluorine are quite similar

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

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

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

87) 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 hydrogen in these acids are not all bound to the phosphorus
c) Phosphorus is a highly electronegative element
d) Phosphorus oxides are less basic

88) Phosphoric acid is syrupy in nature due to
a) a strong covalent bond
b) van der Waals forces
c) Hydrogen bonding
d) None

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

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

91) At low temperatures NO2 dimerises to N2O4.The dimerisation is accompanied by
a) An increase in pressure
b) a decrease in paramagnetism
c) a darkening in colour
d) a formation of colloid

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

93) The salt which on heating gives a mixture of two gases is
a)
b)
c)
d) None of these

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

95) Sal volatile is
a)
b)
c)
d)

96) Red P is used in making
a) Air fresheners
b) Red plastics
c) Red dyes for plastics
d) Safety match striking surface

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

98) Phosphine is generally prepared in the 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

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

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


Answer

Leave a Reply

Your email address will not be published. Required fields are marked *