Chemistry Electro Chemistry Online Mcqs Test

Malik TahirLast Updated: October 14, 2025

Important Electro Chemistry Question and Answer

Total Questions:	192
Time Allowed:	60 Minutes
Total Marks:	192
How to Attempt Test:	Please choose the right Option in MCQ-type question.
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Electro Chemistry Practice Test Online With Explanation

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Page 1 of 8

Chemistry

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

Na and Hg

Na, Pt and graphite

Pt and graphite only

Na and S only

2. 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

0.40

0.25

0.35

0.30

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

1.32

6.1

5.51

5.65

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

Increases gradually

Drops to zero

Increases rapidly

Does not change

5. Specific conductivity of a solution

Depends on mass of electrolyte

Increases with dilution

Decreases with dilution

Remains unchanged with dilution

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

∆ G = -ve, ∆ E = 0

∆ G = +ve, ∆ E = 0

∆ G = -ve

∆ G = 0, ∆E = 0

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

Cl₂O

Na₂O₂

F₂O

Na₂O

8. The solubility of a gas in water depends upon

All of these

Nature of the gas

Pressure of the gas

Temperature

9. 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

6.4 g

12.8 g

3.2 g

2.3 g

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

Vapour pressure of pure benzene decreases by the addition of naphthalene

Boiling point of pure benzene increases by the addition of toluene

Vapour pressure of pure water decreases by the addition of nitric acid

Boiling point of pure water decreases by the addition of ethanol

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

Unsaturated

Saturated

Ideal

Supersaturated

12. An electrolyte

Possesses ions even in solid state

Forms complex ions in solution

Gives ions only when electricity is passed

Gives ions only when dissolved in water

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

Milligram percent

Microgram percent

Parts per million

Gram per million

14. Density of H₂SO₄ in lead accumulator is

1.20g/cm3

1.25g/cm3

1.15g/cm3

1.3g/cm3

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

Electroplating

Making leather

Manufacture of bleach

Rust removal

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

0.1 M Glucose

0.1 M BaCl₂

0.1 M NaCl

0.1 M Sucrose

17. Which of the following is a strong electrolyte?

HCN

CH₃COOH

Ca(NO₃)₂

NH₄OH

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

0.521

0.0186

1.86

0.0521

19. The depression of freezing point is directly proportional to

Molarity of the solvent

Molarity of the solution

Mole fraction of the solution

Molality of the solution

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

750 mm of Hg

800 mm of Hg

780 mm of Hg

760 mm of Hg

21. Reduction always occurs

None of these

At anode

Both A and B

At cathode

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

302 S cm² mol¯¹

128 S cm² mol¯¹

176 S cm² mol¯¹

278 S cm² mol¯¹

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

Heat energy

Magnetic energy

Sound energy

Electrical energy

24. The degree of dissociation of weak electrolyte increases as

Dilution decreases

None

Dilution increases

Pressure increases

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

7.20

3.12

0.217

4.10

Page 2 of 8

26. 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

4 N

0.2 N

2 N

0.4 N

27. Maximum freezing point falls in

Camphor

Benzene

Water

Naphthalene

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

Precipitated

Hydrolyzed

Oxidized

Reduced

29. 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?

18 M

18.4 M

4.18 M

8.14 M

30. Oxidation state of hydrogen in CaH₂ is

-1

-2

31. Decrease in oxidation number is called

All of these

Reduction

Redox

Oxidation

32. Solution with same osmotic pressures are called

Hypotonic

Hypertonic

Normal

Isotonic

33. 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

21.6 g

1.08 g

108 g

10.8 g

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

1.86 c°

Sufficient date not given

0.186 c°

18.6 c°

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

Chlorine

Chloride

Hydrogen

Oxygen

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

1 f

2 M

1 M

1 N

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

Ionic concentration

Diffusion rate of the solute

Flow of solvent from a concentrated to a dilute solution

Elevation in boiling point

38. Electricity in voltaic cell is produced due to

Oxidation

Neutralization

Reduction

B + C

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

2.46 atm

12.1 atm

1.21 atm

24.6 atm

40. 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

0.20

0.80

0.60

0.75

41. In a Galvanic cell

Electrical energy is converted into chemical energy

Chemical energy is converted into heat

Electrical energy is converted into heat

Chemical energy is converted into electricity

42. Secondary cell is

Non rechargeable

Rechargeable

Daniel cell

Electrolytic cell

43. 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

1.06 x 10²

1.06 x 10³

1.06 x 10⁴

44. Strong reducing agents have

Greater negative value of standard reduction potential

Greater positive value of standard reduction potential

Lesser positive value of standard reduction potential

None of these

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

Produce high purity water

Remove adsorbed oxygen from electrode surfaces

Generate heat

Create potential difference between two electrodes

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

0.1 molal

0.5 molal

1.1 molal

1 molal

47. What are the ions present in water?

H2O

H+ and OH-

H and OH

H2 and O

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

1.0

1.5

0.5

2.0

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

All

1 normal

1 molar

1 molal

50. 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

0.1 M

0.15 M

0.05 M

0.2 M

Page 3 of 8

51. Standard hydrogen electrode has an arbitrarily fixed potential

1.00 volt

0.10 volt

None of these

0.00 volt

52. Potential of Zn is called

Redox

Oxidation

Reduction

It has not potential

53. In a Galvanic cell, the electrons flow from

Anode to cathode through the solution

Anode to cathode through the external circuit

Cathode to anode through the solution

Cathode to anode through the external circuit

54. In a chemical reaction, oxidation process involves

Oxidation number neither increases nor decreases

Increase in oxidation number of element

Decrease in oxidation number of element

Increase in oxidation number of the elements in reactants

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

0.001

0.01

100

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

0.186

0.512

0.0512

0.80

57. Azeotropic mixture of HCl and water has

20.2% HCl

22.2% HCl

48% HCl

36% HCl

58. 18g of glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to

1/51

1/5

5.1

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

Both

Oxidation

Reduction

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

Na₂SO₄

CH₃ CooNH₄

NH₄Cl

NaCl

61. Colligative properties are the properties of

Both a and b

Concentration solutions behave as nearly non – ideal solutions

Dilute solution which behave as nearly ideal solution

Neither a nor b

62. 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?

15.9 gm

31.8 gm

12.7 gm

63.5 gm

63. Temperature for standard electrode potential is

310 K

273 K

25 C°

300 K

64. 2.5 faradays of electricity is passed through solution of CuSO₄. The number of gram equivalents of copper deposited on the cathode would be

1.25

None of these

1 2

2.5

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

14.25%

9.09%

13.1%

11.2%

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

Standard reduction potential

Cell voltage

Standard oxidation potential

Ionization potential

67. Vant Hoff’s factor of Ca(NO₃)₂ is

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

H₃PO₂

H₄P₃O₇

H₃PO₃

H₃PO₄

69. The Vant Hoff factor (i) accounts for

The extent of dissolution of solute

Degree of solubilization of solute

The extent of dissociation of solute

The degree of decomposition of solution

70. Oxidation in a chemical reaction involves

Both are possible

Decrease in oxidation number

Increase in oxidation number

Increase in oxidation number of all the elements on reactant side

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

Viscosity

Surface tension

Osmotic pressure

Refractive index

72. 96500 C electricity is passed through CuSO₄. The amount of copper precipitated is

0.25 mole

1.0 mole

2.00 mole

0.5 mole

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

Ca(OH)₂

NaOH

KOH

NH₄OH

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

Henry’s law

Raoult’s law

Arrhenius law

Ostwald’s law

75. Molarity of water is

55.5

Page 4 of 8

76. If liquids A and B form an ideal solution

The entropy of mixing is zero

The enthalpy of mixing is zero

The free energy as well as the entropy of mixing are each zero

The free energy of mixing is zero

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

45.1

40.5

39.6

42.7

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

Melting point

Sublimation point

Boiling point

Inversion point

79. 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

2 N

3 N

9 N

1 N

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

Anode

Electrode

Cathode

None of these

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

30,000 s

10 s

10,000 s

30 s

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

Gains electrons

Acts as a catalyst

pH is changed

Loses electrons

83. A redox reaction involves

Proton transfer

Ion combination reaction

Electron transfer

A reaction in a solution

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

Electrolytic cell

Fuel cell

Galvanic cell

Daniel cell

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

Br₂ + 2e – → 2Br –

Na⁺ + e– → Na

2Br– → Br₂ + 2e –

Na → Na⁺ + e–

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

None of these

Electrorefining

Both A and B

Electroplating

87. Cathode provides electrons to

+Ve ion

Does not provide any electron

-Ve ion

Neutral atom

88. 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

2.0 x 10¹¹

4.0 x 10¹²

1.0 x 10²

1.0 x 10¹⁰

89. During a redox reaction, an oxidizing agent

Loses electrons

Is oxidized

Is hydrolysed

Gains electrons

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

0.1 N HCl

Glass

0.1 N NaCl

Graphite

91. 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

20 C

120 C

240 C

4 C

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

1 – α

1 + 2 α

1 – 2 α

1 + α

93. 0.5 M of H₂SO₄ is diluted from 1 liter to 10 liter, normality of resulting solution is

0.1N

1 N

11 N

10 N

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

Electrolysis

Induction

Electroplating

Conduction

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

More voltage is required to reduce H⁺ at Hg than at Pt

Na is dissolved in Hg while it does not dissolve in Pt

Conc. Of H⁺ ions is when Pt electrode is taken

Hg is more inert than Pt

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

+ 0.35

– 1.17 V

– 0.35 V

+ 1.17 V

97. In alkaline battery anode is made up of

MnO₂

Cadmium

AgO₂

98. Best way to prevent rusting iron is by

Making iron cathode

Both of these

Putting it in saline water

None of these

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

Pure distilled water

Molten NaCl

Dilute solution of glucose

Chloroform

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

Ionization potential

Standard electrode potential

Electric change

Electroplating

Page 5 of 8

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

2.15 cm¯³

1.25 cm¯³

1.81 cm¯³

1.15 cm¯³

102. 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

0.5

2.0

1.5

1.0

103. Alkaline battery has a voltage of

3.5V

1.5V

2.5V

4.5V

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

510 sec

642 sec

102 sec

12157.48 sec

105. 96500 C of electricity liberates from CuSO₄ solution

31.75 g of Cu

100 g of Cu

96500 g of CU

63.5 g of Cu

106. Choose the best reducing agent among the following

Br¯¹

Cl¯¹

I¯¹

F¯¹

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

Slightly less than the total volume of the components

Equal to the total volume of the components

None of these

Slightly more than the total volume of the components

108. Salt bridge transfers

Electrons

Solvent particles

Anions

Current

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

Distribution law

Raoult’s law

Henry’s law

Ostwald’s dilution law

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

20 ml

10 ml

80 ml

40 ml

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

Very high negative values reduction potential

Very low ionization potential values

Reduction potentials are negative

Very high positive value of reduction potential

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

A voltaic cell

An electrolytic cell

A chemical cell

A galvanic cell

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

2 g

20 g

10 g

1 g

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

NaCl

BaCl₂

KCl

MgCl₂

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

None

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

Fractional distillation

None of these

Vacuum distillation

Distillation

117. 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)

0.176 V

0.399 V

0.281 V

0.222 V

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

Less than that of water

More than that of H₂O

Equal to that of ethanol

Equal to that of water

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

1.5

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

Sum of reduction and oxidation potentials

Lesser

None

Greater

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

Decrease rapidly

Drops to zero

Decreases slowly

Does not change

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

The standard reduction potential of Li⁺/Li is lower than that of Cu²+/Cu

The standard reduction potential of Cu²+/Cu is lower than that of Li⁺/Li

The standard oxidation potential of Li/Li⁺ is lower than that of CuCu²⁺

Li is smaller in size as compared to Cu

123. Mole fraction of pure water is

Exactly equal to one

None of these

Slightly greater than one

Slightly less than one

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

Both oxidation and reduction

Neither oxidation and reduction

Oxidation

Reduction

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

0.5

0.05

2.05

0.25

Page 6 of 8

126. 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

A > C > B

B > C > A

C > B > A

A > B > C

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

760 mm of Hg

Slightly more than 1 atom

2.5 atom

750 torr

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

60 g

40 g

4 g

6 g

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

8 N

2 N

6 N

4 N

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

131. Chemical used in salt bridge is

KBr

KNO3

KOH

KCI

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

HgCl₂

ZnCl₂

Hg₂Cl₂

CuSO₄

133. In electrolytic cell, electricity in carried out by

Neutralization

Non-spontaneous reaction

All

Spontaneous reaction

134. 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

72 torr

20 torr

68 torr

140 torr

135. When common salt is dissolved in water

B.P of water remain constant

B.P of water decrease

Any possibility

B.P of water increase

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

Galvanic cell

Fuel cell

Dry cell

Electrolytic cell

137. Molton NaCl conducts electricity due to the presence of

Free electrons

Free molecules

Free ions

Atoms of Na and Cl.

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

48250

193000

96500

10000

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

58.5g NaCl/100ml

20g NaCl/100ml

5.58g NaCl/100m

10.0g NaCl/100ml

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

None of these

O₂,H₂

O₂, Na

O₂, SO₂

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

Sulphuric acid

Nitric acid

Boric acid

Phosphorus acid

142. The best reducing agent is

Cl¯

Br¯

F¯

I¯

143. Half cells are interconnected through

Salt Bridge

No connection exists

Wire

Electric circuit

144. In an electrolytic cell current flows

From cathode to anode in outer circuit

From cathode to anode inside the cell

From anode to cathode in an outer circuit

From anode to cathode inside the cell

145. 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

[Pt(NH₃)₄Cl₄]

[Pt(NH₃)₄Cl₂]Cl₂

[Pt(NH₃)₄Cl₃]Cl

[Pt(NH₃)₄Cl]Cl₃

146. Pure water does not conduct electricity because it

Is neutral

Is almost unionized

Has low boiling point

Is readily decomposed

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

Ag⁺

I₂

Pb²⁺

148. In alkaline battery the anode is made up of

AgO2

MnO2

Cadmium

149. Salt bridge transfers

Current

Anion

Electrons

Ions

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

1 ampere

2 ampere

1 faraday

1 coulomb

Page 7 of 8

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

Higher

Not particular

Lower

In middle

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

Gold has higher reduction potential then iron

Iron rusts

Gold has lower reduction potential then iron

Gold is denser

153. 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

11.2 cm³

56 cm³

550 cm³

5.6 cm³

154. Voltaic cell can be recharged by

By addition of fresh solution

By heating it

By replacing external circuit with external source of electricity

By removal of solution

155. Which of the following statements is FALSE?

Oxidation and reduction half-reactions occur at electrodes in electrochemical cells.

All voltaic (galvanic) cells involve the use of electricity to initiate nonspontaneous chemical reactions

Reduction occurs at cathode

All electrochemical reactions involve the transfer of electrons

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

A strong acid and its salt of a strong base

Weak acid and its salt of weak base

Strong acid and its salt of weak base

Weak acid and its salt of strong base

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

None of these

Na⁺

Cl¯

Both Na⁺ and CI¯

158. 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

96.5

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

1 to 5

0 to 5.

0 to –3

2 to 5

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

4 g

1 g

2 g

5 g

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

Electrochemical equivalent

One gm. Equivalent weight

One gm. atomic weight

None of these

162. 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)

3.33

0.0033

33.3

0.333

163. 8 g of NaOh is dissolved in 500 cm³ of solution, its molarity is:

0.8 M

0.04 M

0.4 M

0.2 M

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

165. Oxidation number of carbon in NaHCO₃ is

-6

166. Units of molarity are

Mol/lit

Kg/lit

Gm/lit

None of these

167. 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:

22400 cm³

112 cm³

1.008 g

224 cm³

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

0.01

0.0196

0.1

0.2

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

0.3

0.6

0.9

0.2

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

0.2

0.01

0.0196

0.1

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

172. 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

0.66 cm¯¹

1.12 cm¯¹

0.142 cm¯¹

0.918 cm¯¹

173. The reference electrode is made by using

Hg₂Cl₂

CuSO₄

HgCl₂

ZnCl₂

174. The conductivity of strong electrolyte

Decreases on dilution

Increases on dilution slightly

Does not change on dilution

Depends on density of electrolyte itself.

175. Camphor is often used in molecular mass determination because

It is solvent for organic substances

It is volatile

It is readily available

It has a very high cryoscopic constant

Page 8 of 8

176. 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

S² m² mol¯²

S m² mol¯¹

S² m² mol

S m mol¯¹

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

Chemical energy

None of these

Heat energy

Electrical energy

178. Metals usually conduct electricity because

In metals the ions are free to more

Metals are decomposed by current

They are mobile electrons in the metallic structure

Metals have high resistance

179. Density of H₂SO₄ in lead accumulator is

1.25g/Cm³

1.15 g/Cm³

120 g Cm³

1.2 g/Cm³

180. The unit of specific conductivity is

Ohm¯¹ cm

Ohm cm¯²

Ohm cm¯¹

Ohm¯¹ cm¯¹

181. Electrode potential of Zn is

Reduction

Oxidation

Depends on the nature of the coupled electrode

Oxidation-reduction

182. The art of electroplating was given by

Faraday

Brugan

Thomas Gradam

Edison

183. Which has maximum oxidation number

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

53.07 kJ

106.15 kJ

175.4 kJ

212.3 kJ

185. Corrosion is basically a

Electrochemical phenomenon

Interaction

Union between two light metals and a heavy metal

Altered reaction in presence of H₂O

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

Migration of ions along with oxidation reaction at anode and reduction reaction at cathode

Electrons flow cathode to anode within the electrolytic solution

None of these

Electrons flow from cathode to anode through the external battery

187. Stronger the oxidizing agent, greater is the

Redox potential

e.m.f of cell

Oxidation potential

Reduction potential

188. Corrosion reactions are

Spontaneous redox reactions

Spontaneous acid–base reactions

None of these

Non-spontaneous redox reactions

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

Galvanization

Electrolysis

Photo electrolysis

Cathodic protection

190. Reaction takes place at anode is

Ionization

Hydrolysis

Reduction

Oxidation

191. Pick out the wrong statement. In electrochemical cell

Salt bridge maintains the electrical neutrality of the solution

Electrons are released at anode

Chemical energy is converted into electrical energy

Cathode is regarded as negative electrode

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

2.16 g

1.08 g

0.27 g

0.54 g

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