Quiznetik

Chemistry | Set 12

1. Which of the following is an essential element used in the synthesis of proteins and other compounds?

Correct : D. Nitrogen

2. Stilton is a –

Correct : A. Semiconductor

3. The orientation of an atomic orbital is governed by –

Correct : B. magnetic quantum number

4. Maximum permissible concentration of total hardness in drinking water is –

Correct : C. 200

5. Electric fuse is an alloy of –

Correct : A. tin and lead

6. Which of the following is the major constituent of LPG?

Correct : D. Butane

7. Ozone layer is present in -

Correct : C. Stratosphere

8. Taj Mahal is greatly affected due to –

Correct : B. Acid rain

9. The most abundant constituent of atmospheric air is –

Correct : D. nitrogen

10. In the periodic table of elements, on moving from left to right across a period, the atomic radius –

Correct : A. decreases

11. The wire of flash bulbs is made up of –

Correct : A. Mg

12. Which of the following has the highest penetrating power?

Correct : C. y-ray

13. Radiations which is not emitted during radioactivity is –

Correct : D. Cathode rays

14. Citric acid is present in free form in –

Correct : D. Lemon

15. Ultraviolet rays can be used in water treatment as –

Correct : D. Disinfectant

16. The heaviest naturally occurring element is:

Correct : D. Uranium

17. Vinegar is used as a condiment, and in the pickling of vegetables and other foods. What is the constituent of vinegar?

Correct : C. Ethanoic acid

18. Which of the following is used as a moderator in nuclear reactors?

Correct : B. Graphite

19. The inert gas which is substituted for nitrogen in the air used by deep sea divers for Breathing is:

Correct : D. Helium

20. Asbestos is formed of :

Correct : A. Calcium and Magnesium

21. Energy posses by a body in motion is called -

Correct : A. Kinetic Energy

22. Natural rubber is a polymer derived from?

Correct : C. isoprene

23. The value of Avogadro Number is -

Correct : B. 6.023 x 1023

24. In silvery paints, the main constituent present is -

Correct : A. Aluminium powder

25. Which one of the following is-a greenhouse gas?

Correct : C. Carbon dioxide

26. The gas involved in Bhopal incident was -

Correct : D. Methyl isocyanide

27. Alcohol prepared by the distillation of wood is:

Correct : B. Methyl alcohol

28. The metal that is used as a catalyst in the hydrogenation of oils is -

Correct : B. Ni

29. The particle required to continue the chain process of Uranium fission is –

Correct : C. Neutron

30. Which of the following is used to increase the anti-knocking property of petrol?

Correct : B. Tetraethyl lead

31. Chemical name of bleaching powder is

Correct : B. Calcium hypochlorite

32. Alcoholic OH) group can be identified by :

Correct : C. FeCl3 Test

33. When ice cubes are made, the entropy of water –

Correct : B. decreases

34. In arc welding, Argon is used because of its -

Correct : A. Low reactivity with metal

35. Kinetics is the study of:

Correct : D. All of these are correct

36. Superconductivity is a material property associated with -

Correct : C. a loss of thermal resistance

37. What role does enzyme pepsin play?

Correct : C. It converts proteins into peptones

38. Water gas is the mixture of –

Correct : C. carbon monoxide and hydrogen

39. Hardness of the water is commonly measured in terms of -

Correct : A. Calcium carbonate equivalents

40. One property of ammonia is –

Correct : D. Its aqueous solution turns red litmus blue

41. ‘Aerosol’ is -

Correct : A. Suspended solid particles in air

42. Bridgmanite is –

Correct : C. Earth's most abundant mineral

43. The molecular mass of a has is –

Correct : A. twice its vapour pressure

44. Carbon footprint can be reduced by –

Correct : A. All of these

45. Thermal electricity is generated by using which of these?

Correct : C. Coal, Natural Gas and Petroleum

46. The mass number of a nucleus is –

Correct : D. sometimes more - and somtimes equal to its atomic number

47. Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has –

Correct : C. stable half filled 2p sub level

48. Graphite is used in nuclear reactors for-

Correct : A. reducing the speed of fast neutrons

49. Bleaching powder is prepared by passing –

Correct : A. Chlorine over slaked lime

50. Acid rain is caused due to pollution of atmosphere by –

Correct : B. oxides of nitrogen and sulphur

51. The working of a dry cell is based on -

Correct : D. Electrolysis

52. Which of the following is the correct sequence of countries in terms of maximum carbon dioxide emission?

Correct : A. China, USA, European Union, India

53. Potassium Permanganate is used for purifying drinking water, because                 .

Correct : B. It is an oxidising agent

54. Oxide of sulphur present in the atmosphere are washed down by rains to cause –

Correct : A. Depletion of fossil fuel reserves

55. An emulsifier is an agent which –

Correct : A. stabilises an emulsion

56. Air is said to be saturated when -

Correct : A. it contains maximum content of water vapour

57. Which one of the following group of gases contribute to the "Green House Effect"?

Correct : A. Carbon dioxide and Methane

58. Methanol cannot be dried with anhydrous CaCl2 because -

Correct : C. it forms a solid CaCl2 × 4CH3OH

59. Acid rain is caused by the pollution of environment by –

Correct : C. Nitrous oxide and Sulphur dioxide

60. What are the components responsible for acid rain?

Correct : B. Sulphur dioxide (SO2) and Nitrogen oxides (NOx)

61. Thermal electricity is generated by using which of these?

Correct : C. Coal, Natural Gas and Petroleum

62. Synthetic detergents are made from –

Correct : B. Sodium salt of benzene sulphonic acid

63. The open "Sigrees” or coal stoves often require fanning to sustain burning because of

Correct : A. tendency of carbon dioxide to form a layer along with dust smoke

64. Antacid tablets consist of –

Correct : B. Hydroxides of magnesium and aluminium

65. Acid rain is caused by the pollution of environment by -

Correct : D. nitrous oxide and sulphur dioxide

66. Synthetic detergents are prepared from

Correct : C. hydrocarbons of petroleum

67. Metals have             .

Correct : A. High melting and boiling point

68. Soap helps in better cleaning of clothes because -

Correct : B. It reduces the surface tension of solution

69. Acid rain is caused by, the pollution of environment by -

Correct : A. carbon dioxide and nitrogen

70. The enormous amount of energy released in an explosion of an atomic bomb is due to the -

Correct : D. conversion of neutrons into protons

71. Organic food is supposed to be better for human consumption because –

Correct : B. It is grown without the use of chemicals & synthetic pesticides

72. Nitrogen fixation is a process of -

Correct : D. Conversion of molecular nitrogen to ammonia

73. What are soaps?

Correct : C. Sodium or potassium salts of heavier fatty acids

74. Electrolysis of an aqueous solution of copper sulphate using copper electrodes gives

Correct : A. Copper at eathode and oxygen at anode.

75. Phosphorus is kept in water because –

Correct : B. its ignition temperature is very low

76. The relation between bond length and bond energy is -

Correct : C. Higher the bond energy, shorter the bond length

77. In an atomic explosion enormous energy is released which is due to the -

Correct : D. Conversion of mass into energy

78. Sea water is saltier than rain water because –

Correct : C. Rivers wash away salts from earth and pour them into the sea

79. Refrigerators keep food unspoiled because –

Correct : A. at its low temperature, bacteria and moulds are inactive

80. Why is water not suitable for putting out a petrol fire?

Correct : D. Water, being heavy, slips below petrol which thus remains in contact with air and burns

81. All isotopes of the same element have

Correct : C. the same atomic number but different atomic masses

82. Sodium vapour lamps glow with yellow colour. This is due to -

Correct : B. the emission of excess energy absorbed by sodium atoms, in the yellow region of the spectrum

83. Photo chemical smog is a result-ant of the reaction among –

Correct : D. NO2, O3 and peroxy acetyl nitrate in the presence of Sunlight

84. During the formation of a chemical bond -

Correct : A. energy decreases

85. Cyanide poisoning causes death in seconds because -

Correct : D. It causes cardiac arrest

86. Iron and manganese present as pollutants in water cannot be re-moved by -

Correct : B. chlorination

87. Which among the following is false about acids?

Correct : D. They are bad conductor of electricity in aqueous solution

88. What are isobars?

Correct : B. Elements with different atomic number but same mass number

89. Which of the following statements is true about Methane?

Correct : D. All of the above

90. Sulphur dioxide level in the atmosphere can be reduced by using -

Correct : D. low - sulphur fuels

91. Chlorine atom and chloride ions -

Correct : A. Have an equal number of protons

92. An atom of an element with mass number 23 and atomic number 11 will have-

Correct : B. 11 protons, 12 neutrons and 11 electrons

93. Atoms of different elements have -

Correct : C. different atomic number and different number of valence electrons

94. The molecular mass of a gas is –

Correct : A. twice its vapour pressure

95. Hydrogen is not found in atmosphere because –

Correct : B. it is the lightest gas

96. The mass number of a nucleus is -

Correct : B. the sum of the number of protons and neutrons present in the nucleus

97. What are transition elements?

Correct : A. Elements whose two outermost shells are incomplete

98. A balloon filled with helium rises in air because –

Correct : C. helium is less dense than air

99. Aqua regia is a 1 : 3 mixture, by volume, of –

Correct : A. conc, nitric acid and conc. hydrochloric acid

100. The freezer in a refrigerator is fitted near the top –

Correct : C. it facilitates convection currents