P – Block Elements – MCQs – 2

1) When iron is heated with conc. HNO3
a) NO is formed
b)
c)
d) It becomes passive

2) The passivity of iron results due to the formation of a thin protective layer of
a) Iron oxide
b) Ferric nitrate
c)
d) NO

3) Which of the following metals is/ are not rendered passive on treatment with conc. HNO3 ?
a) Iron
b) Aluminium
c) Chromium
d) None of these

4) Ammonia is commercially prepared by
a)
b)
c) Contact process
d) Lead Chamber process

5) In the reaction, + 3H22NH3the forward reaction is exothermic and the backward reaction is endothermic, we can produce heat by
a)
b)
c)
d) None of the above

6) In the Habers process, metallic oxides catalyse reaction between gaseous nitrogen and hydrogen to yield ammonia whose volume (STP) relative to the total volume of the reactants taken (STP) would be
a) One-fourth
b) One-half
c) The same
d) Three-fourth

7) In the Habers process for the manufacture of ammonia, iron is used as a catalyst and molybdenum is used as a promoter. The function of the promoter is
a) To increase the rate of combination of gases
b) To raise the activation energy of the reaction
c) To increase the activity of the catalyst
d) To increase the yield of ammonia

8) Nitrate ion is isoelectronic with
a)
b)
c)
d)

9) The bond angle in the nitrate ion is
a)
b)
c)
d)

10) The gas obtained when bleaching powder is treated with a warm concentrated solution of NH3 is
a)
b)
c) NO
d)

11) The other products obtained along with water when NH3 is passed over heated CuO are
a)
b)
c)
d) None of these

12) Animals die in a nitrogen atmosphere because
a) It is poisonous
b) It is heavier than air
c) Of lack of oxygen
d) It destroys haemoglobin

13) Nitrogen is used to fill electric bulbs because
a) It is lighter than air
b) It makes the bulb give more light
c) It does not support combustion
d) It is non-toxic

14) Which of the following is a solid compound ?
a)
b)
c) NO
d)

15) Which of the following statements is true for HNO2 ?
a) It cannot act as a reducing agent
b) It cannot act as an oxidising agent
c) It can act both as oxidant and reductant
d) N in nitrous acid is in + 5 oxidation state

16) Which of the following does not give NO2 on heating ?
a)
b)
c)
d)

17) Nitrous oxide is formed by heating
a)
b)
c)
d)

18) PCI5 exists but NCI5 does not because
a) Nitrogen has no vacant orbitals
b) Nitrogen is unstable
c) The nitrogen atom is much smaller
d) Nitrogen is highly inert

19) Which of the following is a true acidic anhydride?
a) CO
b) NO
c)
d)

20) A solution containing NH4CI and NaNO2 produces on boiling
a) Nitrous oxide
b) Nitrogen
c) Nitrogen dioxide
d) Ammonia

21) The action of concentrated nitric acid on metallic tin produces
a) Stannous nitrite
b) Stannous nitrate
c) Stannic nitrate
d) Hydrated stannic oxide

22) Which of the following is most electronegative ?
a) O
b) S
c) Te
d) Se

23) Hydrogen is evolved by the action of cold dil. HNO3 on
a) Fe
b) Mn
c) Cu
d) Al

24) A hydride of nitrogen which is acidic is
a)
b)
c)
d)

25) When conc. HNO3 is heated with P2O5 it forms
a)
b) NO
c)
d)

26) Tritium is an isotope of
a) Hydrogen
b) Tellurium
c) Titanium
d) Tantalum

27) In Habers process for the manufacture of ammonia, the catalyst used is
a) Finely divided nickel
b) Finely divided molybdenum
c) Finely divided iron
d) Finely divided platinum

28) The catalyst used in the manufacture of HNO3 by Ostwalds process is
a) Platinum black
b) Finely divided nickel
c) Vanadium pentoxide
d) Platinum gauze

29) The non-combustible hydride among the following is
a)
b)
c)
d)

30) Nitrogen is produced by heating
a)
b)
c)
d)

31) The reddish-brown coloured gas formed when nitric oxide is oxidised by air is
a)
b)
c)
d)

32) HCI is added to the following oxides. Which one would give H2O2 ?
a)
b)
c) BaO
d) None of the above

33) In the laboratory preparation of oxygen, it is collected over
a)
b) Spirit
c) Mercury
d) Kerosene oil

34) Which one of the following molecules contains a lone pair of electrons on the central atom ?
a)
b)
c)
d)

35) On strongly heating Pb (NO3)2 crystals, the gas formed is
a)
b)
c)
d) NO

36) Which one of the following statements, if any, regarding hydrogen peroxide is false?
a) It is a strong oxidizing as well as reducing agent in acidic as well as basic medium
b)
c) It is more stable in a basic solution
d)

37) The oxygen molecule exhibits
a) Paramagnetism
b) Diamagnetism
c) Ferromagnetism
d) Ferrimagnetism

38) Nitrogen combines with metals to form
a) Nitrites
b) Nitrates
c) Nitrosyl chloride
d) Nitrides

39) The isotopes of oxygen are
a)
b)
c)
d) None

40) Permanent hardness can be removed by adding
a)
b)
c) Ca (OCI) Cl
d)

41) The element which is essential in nitrogen fixation is
a) Zinc
b) Copper
c) Molybdenum
d) Boron

42) Which of the following cannot adsorb large volumes of hydrogen gas?
a) Colloidal solution of palladium
b) Finely divided nickel
c) Colloidal ferric hydroxide
d) Finely divided platinum

43) The bond angle in the O3 molecule is
a)
b)
c)
d)

44) The starting material in the Birkeland and Eyde process for the manufacture of nitric acid is
a) Ammonia
b)
c) Air
d) Chile saltpetre

45) Which does not show allotropy?
a) O
b) S
c) Se
d) None of the above

46) Which of the following fluorides does not exist?
a)
b)
c)
d)

47) Aqua regia is a mixture of
a)
b)
c)
d)

48) Nitrates of all metals are
a) Soluble in water
b) Insoluble in water
c) Coloured
d) Unstable

49) Which one of the following properties is not correct for ozone?
a) It oxidises lead sulphide
b) It oxidises potassium iodide
c) It oxidises mercury
d) It cannot act as a bleaching agent

50) Which of the following oxides of nitrogen, NO2 and NO, is/are paramagnetic?
a)
b) NO
c) Both
d) None

51) Which one of the following statements is true for HNO2?
a) It cannot act as a reducing agent
b) It cannot act as an oxidising agent
c) It cannot act both as oxidant and reductant
d) It is stable only in aqueous solution

52) Ammonia is a Lewis base. It forms complexes with cations. Which one of the following cations does not form complexes with ammonia?
a)
b)
c)
d)

53) Which of the following is not correct for N2O ?
a) It is called laughing gas
b) It is nitrous oxide
c) It is not a linear molecule
d) It is least reactive in all oxides of nitrogen

54) In the catalytic oxidation of ammonia an oxide is formed which is used in the preparation of HNO3. This oxide is
a) NO
b)
c)
d)

55) Nitric acid (conc.) oxidises phosphorus to
a)
b)
c)
d)

56) An important method for fixation of atmospheric N2 isthe
a) Fischer Tropsch process
b) Haber process
c) Frasch process
d) Solvay process

57) Which of the following will not give nitrogen dioxide on heating?
a)
b)
c)
d)

58) The most unstable hydride is
a)
b)
c)
d)

59) The order in which the following oxides are arranged according to their decreasing basic nature is
a)
b)
c)
d)

60) Which one of the following metals reacts with water at room temperature?
a) Silver
b) Iron
c) Aluminium
d) Sodium

61) Which of the following acids possesses oxidising, reducing and complex forming properties?
a)
b)
c) HCI
d)

62) Which of the following statements is correct for the manufacture of NH3 by Haber’s process?
a) Low temperature, high pressure, presence of catalyst
b) High temperature, high pressure and catalyst
c) Low temperature and high pressure
d) High temperature and low pressure

63) The oxide that gives hydrogen peroxide on treatment with dilute acid is
a)
b)
c)
d)

64) Of the following, which has three electron bonds in its structure?
a) Nitrous oxide
b) Nitric oxide
c) Dinitrogen trioxide
d) Nitrogen pentoxide

65) The formula of calcium cyanamide is
a)
b)
c)
d)

66) The compound which gives off oxygen on moderate heating is
a) Cupric oxide
b) Mercuric oxide
c) Zinc oxide
d) Aluminium oxide

67) The bond angle H—N—H in the ammonia molecule is
a)
b)
c)
d)

68) Calgon used as a water softener is
a)
b)
c)
d)

69) Which of the following is a saline oxide?
a)
b)
c)
d)

70) The formula of ozone is O3, it is
a) An allotrope of oxygen
b) Compound of oxygen
c) Isotope of oxygen
d) Isomer of oxygen

71) Which is paramagnetic?
a) NO
b)
c)
d)

72) An aqueous solution of hydrogen peroxide is
a) Alkaline
b) Neutral
c) Strongly acidic
d) Weakly acidic

73) Nitric oxide is prepared by the action of HNO3 on
a) Fe
b) Cu
c) Zn
d) Sn

74) In the upper layer of the atmosphere ozone is formed by the
a) Combination of oxygen molecules
b) Action of electric discharge on oxygen molecule
c) Action of UV rays on oxygen
d) None

75) The boiling point of heavy water is
a) 100 degree Celsius
b) 99 degree Celsius
c) 101.4 degree Celsius
d) 110 degree Celsius

76) The strongest base is
a)
b)
c)
d)

77) Which of the following oxides is a peroxide?
a)
b)
c) BaO
d)

78) When AgNO3 is heated strongly, the products formed are
a)
b)
c)
d)

79) Ozone is an important constituent of the stratosphere because it
a) Prevents the formation of smog over large cities
b) Removes poisonous gases of the atmosphere by reacting with them
c) Absorbs ultraviolet radiation which is harmful to human life
d) Destroys bacteria which are harmful to human life

80) Which of the following is not true for ozone?
a) It is a strong sterilizing agent
b) It attacks organic compounds containing carbon-carbon double bond
c) Its molecule is linear
d) It is a more powerful oxidising agent than molecular oxygen

81) Which oxide does not act as a reducing agent?
a) NO
b)
c)
d)

82) Hydrogen peroxide is used as
a) An oxidant only
b) A reductant only
c) An acid only
d) An oxidant, a reductant and an acid

83) The catalytic oxidation of NH3 gives
a) Dinitrogen pentoxide
b) Nitric oxide
c) Nitrogen dioxide
d) Nitrogen

84) Which of the following reactions is employed to produce ozone in the laboratory?
a) Exposure of air to UV light
b)
c)
d) Passage of a silent electric discharge through oxygen

85) Pure nitrogen is prepared in the laboratory by heating a mixture of
a)
b)
c)
d)

86) Which statement is not correct regarding nitrogen?
a) It has a small size
b)
c) It is a typical non-metal
d) d-orbitals are available for bonding

87) Nitrogen is liberated by the thermal decomposition of
a) only
b) only
c) only
d) All the three

88) The number of unpaired electrons in the p-sub-shell of oxygen atom is
a) 1
b) 2
c) 3
d) 4

89) Which of the following gives nitrogen on heating?
a)
b)
c)
d)

90) Concentrated nitric acid oxidises cane sugar to
a)
b)
c)
d) Oxalic acid and water

91) The aqueous solution of ammonia contains the following ions:
a) only
b) only
c) only
d)

92) The volume strength of 1.5 N H2O2 solution is
a) 4.8
b) 8.4
c) 3.0
d) 8.0

93) Hydrogen peroxide molecules are
a)
b)
c)
d)

94) The substance among the following which is soluble in ammonia is
a)
b)
c)
d)

95) SO2 oxidises
a) Mg
b)
c)
d) All

96) A student accidentally splashes few drops of conc. H2SO4 on his cotton shirt. After a while the splashed parts blacken and holes appear. This is because sulphuric acid
a) Dehydrates the cotton with burning
b) Causes the cotton to react with it
c) Heat up the cotton
d) Removes the elements of water from the cotton

97) Ozone reacts with dry iodine to give
a)
b)
c)
d)

98) Which would quickly absorb oxygen?
a) Alkaline solution of pyrogallol
b)
c) Lime water
d)

99) The cyanide ion, and N2 are isoelectronic. But in contrast to , N2 is chemically inert because of its
a) Low bond energy
b) Absence of bond polarity
c) Unsymmetrical electron distribution
d) increased number of electrons in bonding orbitals

100) Which acts both as oxidising as well as reducing agent?
a)
b)
c)
d) HCI


 

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