ECAT Chemistry Electrochemistry Online Test

1. Camphor is often used in molecular mass determination because

2. Specific conductivity of a solution

3. The relative lowering of vapour pressure is equal to mole fraction of the solute. This law is called:

4. The standard EMF of Daniel cell is 1.10 volt. The maximum electrical work obtained from the Daniel cell is

5. Which of the substances Na, Hg, S Pt and graphite can be used as electrodes in electrolytic cells having aqueous solution?

6. Density of H₂SO₄ in lead accumulator is

7. In a Galvanic cell, the electrons flow from

8. Which one of the following substance when dissolved in water give acidic solution

9. 0.5 M of H₂SO₄ is diluted from 1 liter to 10 liter, normality of resulting solution is

10. How much of NaOH is required to neutralize 1500 cm³ of 0.1 N HCl?

11. The cathodic reaction in the electrolysis of dil. H₂SO₄ with Pt electrodes is

12. Same amount of electric current is passed through solution if AgNO₃ and HCl. If 1.08 g of silver is obtained in the first case, the amount of hydrogen liberated as S.T.P. in the second case is:

13. In an electrolytic cell current flows

14. A device which converts electrical energy into chemical energy is called

15. Electrode potential of Zn is

16. Mole fraction of pure water is

17. Prevention of corrosion of iron by Zn coating is called

18. Stronger the oxidizing agent, greater is the

19. Salt bridge transfers

20. Calculate the percentage by weight if NaCl, if 2.0 g of NaCl is dissolved in 20g of water

21. Colligative properties are the properties of

22. Which oxide has +2 oxidation number of oxygen?

23. A solution contains 1.2046 x 10²⁴ hydrochloric acid molecules in one dm³ of the solution. The strength of the solution is

24. Cathodic reaction in the electrolysis of dil. H₂SO₄ is always

25. Reaction takes place at anode is

26. In a hydrogen-oxygen fuel cell, combustion of hydrogen occurs to

27. When electricity is passed through molten Al₂O₃ + Na₃AIF₆ and 13.5 gms of Al are deposited, the number of faraday must be

28. Which of the following solution of H₂SO₄ is more concentrated?

29. Salt bridge transfers

30. Which of the following is the strongest oxidizing agent?

31. Separation of azeotropic mixture into pure components is carried out by

32. What will be the weight of deposited silver on passing 965 coulombs of electricity in solution of AgNO₃?

33. Choose the cell among the following list in which conversation of electrical energy into chemical energy takes place

34. After adding a solute freezing point of solvent decreases to -0.186. Calculate ∆ Tb if Kf = 1.86 and Kb = 0.521

35. In a Galvanic cell

36. Oxidation in a chemical reaction involves

37. Conductivity (Unit : siemen’s S) is directly proportionally to the area of the vessel and the concentration of the solution in it and is inversely proportional to the length of vessel, then the unit of constant of proportionality is

38. For spontaneity of a cell, which is correct?

39. Under the process of rusting of iron, 4Fe + 3O₂ → 2Fe₂O₃, iron is

40. In galvanic cell Zn acts as an anode so its value of standard reduction potential in comparison to coupled electrode would be

41. 8 g of NaOh is dissolved in 500 cm³ of solution, its molarity is:

42. 18g of glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to

43. A current of 9.65 ampere flowing for 10 minutes deposits 3.0 g of the metal which is monovalent. The atomic mass of the metal is

44. Temperature for standard electrode potential is

45. The molarity of the solution containing x grams (NH₄)SO₄ in 500 cm³ of the solution is 0.6. What is x

46. If the standard electrode potential of CU²⁺/Cu electrode is 0.34 V, what is the electrode potential of 0.01 M concentration of Cu²⁺? (T = 298 K)

47. When molten sodium undergoes electrolysis, the ion reduces is

48. The specific conductance of a 0.1 N KCl solution at 23°C is 0.012 ohm¯¹ cm¯¹. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be

49. Out of Cu, Ag, Fe and Zn the metal which can displace all others from their salt solutions is

50. A solution of sodium sulphate was electrolyzed using some inert electrodes. The products at the electrodes are

51. Li occupies higher position in the electrochemical series of metals as compared to Cu since

52. H₂ gas in SHE is filled at a pressure of

53. Decrease in oxidation number is called

54. If a salt bridge is removed between the two half cells, the voltage

55. The EMF of the cell rection Fe²⁺ + zn = Zn²⁺ + feis

56. The ionic strength of a solution containing 0.1 mole/kg of KCl and 0.2 mole/kg of CuSO₄ is

57. Corrosion reactions are

58. Which substances are mixed to form a buffer solution?

59. The molality of 2% NaCl. W/W solution is approximately

60. Sea water has 5.65 x 10¯³ g of dissolved oxygen calculate the conclusion of oxygen in sea water in ppx

61. A smuggler could not carry gold by chemically depositing iron on the gold surface since

62. A 20% solution of NaCl by weight means that

63. 1.0 g of pure calcium carbonate was found to require 50 ml of dilute HCl for complete reaction. The strength of HCl solution is given by

64. The temperature at which the vapour pressure of a liquid becomes equal to external pressure is

65. The + 1 oxidation state of P is found in

66. Metals usually conduct electricity because

67. 96500 C electricity is passed through CuSO₄. The amount of copper precipitated is

68. Pure water does not conduct electricity because it

69. Oxidation state of hydrogen in CaH₂ is

70. Anode electrode element always have _________ position in electrochemical series

71. Equal volumes of ethylene glycol (molar mass = 62) and water (molar mass = 18) are mixed. The depression in freezing point of water is (given Kf of water 1.86 K mol¯¹ kg and specific gravity of ethylene glycol is 1.11)

72. The art of electroplating was given by

73. 96500 C of electricity liberates from CuSO₄ solution

74. Strong reducing agents have

75. Molarity of water is

76. Solution with same osmotic pressures are called

77. A cell constant is generally found by measuring the conductivity of aqueous solution of

78. Calculate the amount of charge flowing in 2 minute in a wire of resistance 10 Ω when a potential difference of 20 V is applied

79. It azeotropic mixture showing positive deviation from Rault’s law, the volume of the mixture is

80. An oxidizing agent in a chemical reaction in the substance which

81. The limiting molar conductivities ʌ’ for NaCl, KBr and KCl are 126, 152 and 150 S cm² respectively. The ʌ’ for NaBr is

82. The unit of specific conductivity is

83. The depression of freezing point is directly proportional to

84. Density of H₂SO₄ in lead accumulator is

85. When a metal is dipped in 1 molar of its solution at 298k, then potential set up is called

86. If the salt bridge is not used between two half cells, then the voltage

87. Time required to deposit one millimole of aluminum metal by the passage of 9.65 amperes through molten electrolyte containing aluminum ion is

88. Which of these is not an application of electrolysis?

89. Which of the following element act as inert electrode?

90. A solution contains A, B and C components. The mole fraction A and C are 0.25 and 0.35 respectively. The mole fraction B will be

91. What is the molality of a solution prepared by dissolving 5 g of toluene in 250 g of Benzene.

92. Wen quantity of electricity passed is one faraday then the mass deposited at the electrode is equal to

93. Which of the following will have the highest boiling point at 1 atm pressure?

94. Which of the following (IM) conducts more electricity?

95. Half cells are interconnected through

96. The number of coulombs required for the deposition of 107.870 g of silver is

97. In the conversion of Br2 to BrO₃¯¹ the oxidation state of bromine changes from

98. Reduction always occurs

99. An aqueous solution freezes at -0.186°C. (Kf = 1.86, Kb = 0.512). What is the elevation in boiling point?

100. During a redox reaction, an oxidizing agent

101. An electrolyte

102. In alkaline battery anode is made up of

103. The degree of dissociation of weak electrolyte increases as

104. If α is the degree of dissociation of Na₂SO₄ the Vant Hoff’s factor (i) used for calculating the molecular mass is

105. Equal volumes of 0.1 M AgNO₃ and 0.2 M NaCl are mixed. The concentration of NO¯₃ ions in the mixture will be

106. The Vant Hoff factor (i) accounts for

107. Electricity in voltaic cell is produced due to

108. If the ionic product of a solution is less than the solubility product, the solution is

109. The standard e.m.f. of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25°C. The equilibrium constant of the reaction would be

110. The number of moles of a solute in 500 cm³, 3M solution is

111. Choose the best reducing agent among the following

112. Which of the statements given below concerning properties of solution, describe a colligaive effect?

113. Hydrogen gas is not liberated when the following metal is added to dil. HCI.

114. Oxidation number of carbon in NaHCO₃ is

115. In electrolytic cell, electricity in carried out by

116. By means of fuel cells, chemical energy may be converted into

117. Standard hydrogen electrode has an arbitrarily fixed potential

118. If liquids A and B form an ideal solution

119. The solubility of a gas in water depends upon

120. 50 mL of 10 N H₂SO₄. 25 mL of 12 N HCl and 40 mL of 5N HNO₃ are mixed and the volume of the mixture is made 1000 mL by adding water. The normality of resulting solution will be

121. Standard reduction electrode potential of three metals A, B and C are respectively + 0.05 V, - 3.0 and -1.2V. The reducing power of

122. The equivalent conductivity of 0.1 M week acid is 100 times less than that at infinite dilution. The degree of dissociation is

123. The amount of electricity that can deposit 108 g of silver from silver nitrate solution is

124. Units of molarity are

125. The reference electrode is made by using

126. A dry alkaline cell has porous Zn anode & MnO₂ as cathode the electrolyte used is

127. An electric current is passed through silver nitrate solution using silver electrodes. 10.79 g of silver was found to be deposited on the cathode if the same amount of electricity is passed through copper sulphate solution using copper electrodes, the weight of copper deposited on the cathode is

128. At room temperature, the mole fraction of a solution in 0.25 and the vapour pressure of the solvent is 0.80 atm. Then the lowering of vapour pressure is

129. In electrolysis of NaCl when Pt electrode is taken then H₂ is liberated at cathode while with Hg cathode it forms sodium amalgam

130. The pressure at which water boils at 101.5 °c is

131. Best way to prevent rusting iron is by

132. The conductivity of strong electrolyte

133. The half-reaction that occurs at the anode during the electrolysis of molten sodium bromide is:

134. A certain current liberate 0.5 g of hydrogen in 2 h. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution?

135. Pick out the wrong statement. In electrochemical cell

136. If 5.85 g of NaCl are dissolved in 90g of water, the mole fraction of NaCl is

137. Chemical used in salt bridge is

138. The osmotic pressure of a dilute solution is directly proportional to the

139. 2.5 faradays of electricity is passed through solution of CuSO₄. The number of gram equivalents of copper deposited on the cathode would be

140. If 18 g of glucose (C₆H₁₂C₆) is present in 1000 g of an aqueous solution of glucose it is said to be

141. An electric current is passed through silver voltmeter connected to a water voltmeter. The cathode of the silver voltammeter is 0.108 g more at the end of the electrolysis. The volume of oxygen evolved at STP is

142. The weight of pure NaOH required to prepare 250 cm³ of 0.1 N solution is

143. When common salt is dissolved in water

144. Which one of the following will be good conductor of electricity?

145. The strength of solution an element whose electrode potential is to be measured

146. Corrosion is basically a

147. Which has maximum oxidation number

148. A cell in which chemical energy is converted into electrical energy is called

149. In alkaline battery the anode is made up of

150. The best reducing agent is

151. An aqueous solution of ethanol in water has vapour pressure

152. Which one of the following is a colligative property?

153. Cathode provides electrons to

154. Which of the following is the use of electrolysis?

155. Which of the following statements is FALSE?

156. Which of the following is a strong electrolyte?

157. How many g of dibasic acid (mol. wt. 200) should be present in 100 ml of the aqueous solution to give 0.1 Normality?

158. Electrolysis is the process in which a chemical reaction takes place at the expense of

159. A 0.001 molal solution of [Pt(NH₃)₄Cl₄] in water had a freezing point depression of 0.0054°C. If Kf for water is 1.80, the correct formulation for the above molecule is

160. Maximum freezing point falls in

161. Secondary cell is

162. The substance having highest conductivity at room temperature among the following is

163. In a solution of CuSO₄ how much time will be required to precipitate 2g copper by 0.5 ampere current?

164. Voltaic cell can be recharged by

165. In the electrolysis of molten sodium chloride, what is the yellow green gas formed?

166. The cryoscopic constant of water is 1.86. The elevation of B.P for a 0.1m solution of a solute in water is

167. Of the following, the metal that cannot be obtained by electrolysis of aqueous solution of their salts are:

168. Molton NaCl conducts electricity due to the presence of

169. Electrochemical series is a list of elements arranged into increasing order to either

170. Alkaline battery has a voltage of

171. Partial pressure of a solution component is directly proportional to its mole fraction. This statement is known as

172. The electrode with more negative value of reduction potential acts as

173. The vapour pressure of two liquids ‘P’ and ‘Q’ are 80 and 60 torr respectively. The total vapour pressure of solution obtained by mixing 3 mole of P and 2 mol of Q would be

174. When electricity is passed through molten electrolyte consisting of alumina and cryolite, 13.5 g of Al are deposited. The number of faradays of electricity passed must be

175. What is the molarity of H₂SO₄ solution that has density of 1.84 gm/cm³ which was at 35°C and contains 98% by weight?

176. If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is

177. The osmotic pressure of 1 m solution at 27°C is

178. What will be the density of H₂SO₄ when lead accumulator is recharged?

179. Which of the following statement is correct for electrolytic cell?

180. The volume of 0.1 M H₂SO₄ required to neutralize completely 40 ml of 0.2 M NaOH solution is

181. Vant Hoff’s factor of Ca(NO₃)₂ is

182. What are the ions present in water?

183. When the solute is present in trace quantities the following expression is used?

184. A redox reaction involves

185. The process of electrical coating of one metal on another to protect, decorate or to have a greater resistance to corrosion is called

186. In a chemical reaction, oxidation process involves

187. When Cu, Ag, Au and Pt are reacted with acids, these metals do not liberate hydrogen, this is due to the reason that

188. Potential of Zn is called

189. When during electrolysis of a solution of AgNO₃, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be

190. Azeotropic mixture of HCl and water has

191. The specific conductance of 0.1 M NaCl solution is 1.06 x 10¯² ohm¯¹mol¯¹. Its molar conductance in ohm¯¹ cm² mol¯¹ is

192. The reference calomel electrode is made from which of the following?