EdgineerX

51. A buffer solution can be prepared from

A. a strong acid and its salt B. a weak acid and its salt with a strong base C. two strong acids D. a strong base alone E. a neutral salt alone

52. The solubility of a sparingly soluble salt decreases on adding a soluble salt with a common ion. This is called

A. the buffer effect B. the common ion effect C. hydrolysis D. the salt bridge effect E. Le Chatelier suppression of Ksp

53. Kc has no units when

A. the reaction is exothermic B. the total number of moles of gaseous reactants equals that of products C. the reaction is at high pressure D. a catalyst is used E. the reaction is irreversible

54. Molality is defined as the number of moles of solute per

A. cubic decimetre of solution B. kilogram of solvent C. litre of solvent D. kilogram of solution E. mole of solvent

55. Which of the following is not a colligative property?

A. elevation of boiling point B. depression of freezing point C. osmotic pressure D. lowering of vapour pressure E. refractive index

56. The molal boiling point elevation constant of water is

A. 0.52 K kg mol-1 B. 1.86 K kg mol-1 C. 5.12 K kg mol-1 D. 0.86 K kg mol-1 E. 2.53 K kg mol-1

57. Raoult's law states that the partial vapour pressure of a component in a solution is proportional to its

A. mass B. mole fraction C. molarity D. molality E. volume fraction

58. A mixture that distils at constant composition and cannot be separated further by fractional distillation is called

A. an ideal solution B. an azeotrope C. a colloid D. a saturated solution E. an emulsion

59. An ideal solution is one in which

A. the enthalpy of mixing is zero and Raoult's law is obeyed B. the volume decreases on mixing C. hydrogen bonding is formed on mixing D. the components react E. the vapour pressure is zero

60. The oxidation number of manganese in potassium permanganate is

A. +2 B. +4 C. +6 D. +7 E. +3

61. The standard electrode potential of the standard hydrogen electrode is taken as

A. +1.00 V B. -1.00 V C. 0.00 V D. +0.76 V E. -0.76 V

62. One faraday of charge is equal to about

A. 9650 C B. 96500 C C. 1.6 x 10^-19 C D. 6.02 x 10^23 C E. 965 C

63. In a galvanic cell, oxidation occurs at the

A. cathode B. anode C. salt bridge D. electrolyte E. porous partition

64. During the discharge of a lead accumulator, the substance formed at both electrodes is

A. lead B. lead dioxide C. lead sulphate D. sulphuric acid E. hydrogen

65. A metal placed higher in the electrochemical series than another will

A. be reduced by it B. displace it from its salt solution C. not react with it D. form a stronger acid E. have a higher electrode potential

66. In an electrolytic cell, electrical energy is

A. produced from a spontaneous reaction B. used to drive a non-spontaneous reaction C. converted into light only D. stored as heat only E. not involved

67. The half life of a first order reaction

A. depends on the initial concentration B. is independent of the initial concentration C. increases as the reaction proceeds D. is proportional to the rate constant E. doubles when concentration doubles

68. A catalyst increases the rate of reaction by

A. increasing the temperature B. lowering the activation energy C. increasing the enthalpy change D. shifting the equilibrium E. increasing the concentration of reactants

69. The order of a reaction is determined by

A. the stoichiometric equation B. experiment C. the molecularity D. the enthalpy change E. the equilibrium constant

70. For a zero order reaction, the rate is

A. proportional to the concentration of the reactant B. proportional to the square of the concentration C. independent of the concentration of the reactant D. inversely proportional to concentration E. zero at all times

71. The Arrhenius equation relates the rate constant to

A. concentration and volume B. temperature and activation energy C. pressure and volume D. pH and temperature E. enthalpy and entropy

72. Enzyme catalysed reactions are highly

A. non-specific B. specific C. endothermic D. irreversible at all temperatures E. independent of pH

73. The modern periodic law states that the properties of elements are a periodic function of their

A. atomic mass B. atomic number C. valency D. density E. atomic volume

74. Across a period from left to right, atomic radius generally

A. increases B. decreases C. remains constant D. increases then decreases E. doubles

75. Ionization energy generally decreases

A. across a period B. down a group C. with decreasing atomic size D. with increasing nuclear charge E. for half filled subshells

Chemistry