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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. Molarity of water is

55.5

2. 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)

0.281 V

0.399 V

0.176 V

0.222 V

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

Vacuum distillation

Fractional distillation

None of these

Distillation

4. 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

5. Oxidation number of carbon in NaHCO₃ is

-6

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

– 0.35 V

+ 1.17 V

– 1.17 V

+ 0.35

7. Maximum freezing point falls in

Water

Benzene

Naphthalene

Camphor

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

128 S cm² mol¯¹

302 S cm² mol¯¹

278 S cm² mol¯¹

176 S cm² mol¯¹

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

0.0512

0.186

0.80

0.512

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

A galvanic cell

An electrolytic cell

A chemical cell

A voltaic cell

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

60 g

6 g

4 g

40 g

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

Oxidation

Reduction

Both oxidation and reduction

Neither oxidation and reduction

13. Solution with same osmotic pressures are called

Isotonic

Hypertonic

Hypotonic

Normal

14. Decrease in oxidation number is called

All of these

Redox

Oxidation

Reduction

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

Na₂O

F₂O

Na₂O₂

Cl₂O

16. Temperature for standard electrode potential is

273 K

300 K

25 C°

310 K

17. 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

550 cm³

56 cm³

5.6 cm³

11.2 cm³

18. 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

19. 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

Boiling point of pure water decreases by the addition of ethanol

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

20. 96500 C of electricity liberates from CuSO₄ solution

100 g of Cu

31.75 g of Cu

96500 g of CU

63.5 g of Cu

21. Density of H₂SO₄ in lead accumulator is

1.20g/cm3

1.15g/cm3

1.25g/cm3

1.3g/cm3

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

0.0196

0.01

0.2

0.1

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

Ionization potential

Standard electrode potential

Electroplating

Electric change

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

Lesser

Sum of reduction and oxidation potentials

None

Greater

25. Which of the following is a strong electrolyte?

CH₃COOH

HCN

NH₄OH

Ca(NO₃)₂

Page 2 of 8

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

2.05

0.5

0.25

0.05

27. 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

1.1 molal

1 molal

0.5 molal

28. Corrosion is basically a

Union between two light metals and a heavy metal

Altered reaction in presence of H₂O

Interaction

Electrochemical phenomenon

29. 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

Very high positive value of reduction potential

Reduction potentials are negative

30. 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)₄Cl]Cl₃

[Pt(NH₃)₄Cl₄]

[Pt(NH₃)₄Cl₃]Cl

[Pt(NH₃)₄Cl₂]Cl₂

31. The solubility of a gas in water depends upon

Nature of the gas

Temperature

All of these

Pressure of the gas

32. Which of the following statements is FALSE?

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

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

All electrochemical reactions involve the transfer of electrons

Reduction occurs at cathode

33. The best reducing agent is

Cl¯

Br¯

F¯

I¯

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

MgCl₂

NaCl

BaCl₂

KCl

35. In a Galvanic cell, the electrons flow from

Anode to cathode through the external circuit

Anode to cathode through the solution

Cathode to anode through the solution

Cathode to anode through the external circuit

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

12.1 atm

2.46 atm

1.21 atm

24.6 atm

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

0 to –3

2 to 5

0 to 5.

1 to 5

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

Chemical energy

Electrical energy

Heat energy

None of these

39. 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

0.4 N

0.2 N

2 N

40. 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 2

2.5

1.25

None of these

41. 18g of glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to

1/5

5.1

1/51

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

0.1 N NaCl

Glass

Graphite

0.1 N HCl

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

Henry’s law

Distribution law

Ostwald’s dilution law

Raoult’s law

44. Oxidation in a chemical reaction involves

Decrease in oxidation number

Increase in oxidation number

Increase in oxidation number of all the elements on reactant side

Both are possible

45. In electrolytic cell, electricity in carried out by

Spontaneous reaction

Neutralization

All

Non-spontaneous reaction

46. 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

240 C

20 C

120 C

4 C

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

1.5

2.0

0.5

1.0

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

0.66 cm¯¹

0.918 cm¯¹

0.142 cm¯¹

1.12 cm¯¹

49. During a redox reaction, an oxidizing agent

Is oxidized

Gains electrons

Loses electrons

Is hydrolysed

50. Stronger the oxidizing agent, greater is the

Redox potential

Reduction potential

Oxidation potential

e.m.f of cell

Page 3 of 8

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

H₃PO₂

H₄P₃O₇

H₃PO₃

H₃PO₄

52. Reaction takes place at anode is

Hydrolysis

Oxidation

Reduction

Ionization

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

1 M

1 f

1 N

2 M

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

0.217

3.12

7.20

4.10

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

Does not change

Decrease rapidly

Decreases slowly

Drops to zero

56. Corrosion reactions are

Spontaneous redox reactions

Spontaneous acid–base reactions

None of these

Non-spontaneous redox reactions

57. In alkaline battery anode is made up of

MnO₂

AgO₂

Cadmium

58. Cathode provides electrons to

+Ve ion

Does not provide any electron

-Ve ion

Neutral atom

59. Pure water does not conduct electricity because it

Is almost unionized

Is neutral

Has low boiling point

Is readily decomposed

60. Electrode potential of Zn is

Reduction

Oxidation

Depends on the nature of the coupled electrode

Oxidation-reduction

61. Strong reducing agents have

Greater negative value of standard reduction potential

Lesser positive value of standard reduction potential

Greater positive value of standard reduction potential

None of these

62. 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

68 torr

140 torr

72 torr

20 torr

63. 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 10⁴

1.06 x 10³

1.06 x 10²

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

2.15 cm¯³

1.81 cm¯³

1.25 cm¯³

1.15 cm¯³

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

Unsaturated

Saturated

Supersaturated

Ideal

66. 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

67. 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

5.65

5.51

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

None of these

Slightly more than the total volume of the components

Slightly less than the total volume of the components

Equal to the total volume of the components

69. Which has maximum oxidation number

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

Nitric acid

Sulphuric acid

Phosphorus acid

Boric acid

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

5.58g NaCl/100m

20g NaCl/100ml

10.0g NaCl/100ml

58.5g NaCl/100ml

72. In a chemical reaction, oxidation process involves

Increase in oxidation number of element

Increase in oxidation number of the elements in reactants

Decrease in oxidation number of element

Oxidation number neither increases nor decreases

73. Specific conductivity of a solution

Remains unchanged with dilution

Depends on mass of electrolyte

Increases with dilution

Decreases with dilution

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

0.186 c°

1.86 c°

18.6 c°

Sufficient date not given

75. Choose the best reducing agent among the following

Br¯¹

Cl¯¹

I¯¹

F¯¹

Page 4 of 8

76. An electrolyte

Gives ions only when dissolved in water

Gives ions only when electricity is passed

Forms complex ions in solution

Possesses ions even in solid state

77. In alkaline battery the anode is made up of

MnO2

AgO2

Cadmium

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

Cell voltage

Standard reduction potential

Ionization potential

Standard oxidation potential

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

Boiling point

Inversion point

Sublimation point

Melting point

80. Units of molarity are

None of these

Kg/lit

Mol/lit

Gm/lit

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

82. Alkaline battery has a voltage of

1.5V

3.5V

4.5V

2.5V

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

5 g

2 g

4 g

1 g

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

Gram per million

Milligram percent

Microgram percent

Parts per million

85. 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?

12.7 gm

15.9 gm

31.8 gm

63.5 gm

86. 96500 C electricity is passed through CuSO₄. The amount of copper precipitated is

1.0 mole

0.5 mole

2.00 mole

0.25 mole

87. What are the ions present in water?

H2O

H and OH

H2 and O

H+ and OH-

88. If liquids A and B form an ideal solution

The entropy of mixing is zero

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

The enthalpy of mixing is zero

The free energy of mixing is zero

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

Acts as a catalyst

pH is changed

Gains electrons

Loses electrons

90. Half cells are interconnected through

No connection exists

Wire

Electric circuit

Salt Bridge

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

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

1 g

20 g

2 g

10 g

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

Osmotic pressure

Surface tension

Refractive index

Viscosity

94. Pick out the wrong statement. In electrochemical cell

Salt bridge maintains the electrical neutrality of the solution

Cathode is regarded as negative electrode

Chemical energy is converted into electrical energy

Electrons are released at anode

95. Standard hydrogen electrode has an arbitrarily fixed potential

None of these

1.00 volt

0.00 volt

0.10 volt

96. Electricity in voltaic cell is produced due to

Neutralization

Oxidation

Reduction

B + C

97. Voltaic cell can be recharged by

By heating it

By replacing external circuit with external source of electricity

By removal of solution

By addition of fresh solution

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

9.09%

13.1%

14.25%

11.2%

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

Weak acid and its salt of strong base

Strong acid and its salt of weak base

A strong acid and its salt of a strong base

Weak acid and its salt of weak base

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

Gold has lower reduction potential then iron

Iron rusts

Gold has higher reduction potential then iron

Gold is denser

Page 5 of 8

101. 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

4.0 x 10¹²

1.0 x 10¹⁰

1.0 x 10²

2.0 x 10¹¹

102. In a Galvanic cell

Electrical energy is converted into chemical energy

Electrical energy is converted into heat

Chemical energy is converted into heat

Chemical energy is converted into electricity

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

0.27 g

0.54 g

2.16 g

1.08 g

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

Not particular

In middle

Lower

Higher

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

Electrorefining

Both A and B

None of these

Electroplating

106. 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

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

NaCl

NH₄Cl

Na₂SO₄

CH₃ CooNH₄

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

Induction

Conduction

Electroplating

Electrolysis

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

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

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

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

510 sec

12157.48 sec

102 sec

642 sec

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

1 molal

All

1 normal

1 molar

112. Best way to prevent rusting iron is by

None of these

Making iron cathode

Putting it in saline water

Both of these

113. Metals usually conduct electricity because

They are mobile electrons in the metallic structure

Metals have high resistance

In metals the ions are free to more

Metals are decomposed by current

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

Hg₂Cl₂

ZnCl₂

HgCl₂

CuSO₄

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

0.2

0.9

0.6

0.3

116. The conductivity of strong electrolyte

Does not change on dilution

Increases on dilution slightly

Depends on density of electrolyte itself.

Decreases on dilution

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

Anode

None of these

Cathode

Electrode

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

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

Chlorine

Chloride

Hydrogen

Oxygen

120. Potential of Zn is called

Reduction

Oxidation

It has not potential

Redox

121. Density of H₂SO₄ in lead accumulator is

1.15 g/Cm³

1.2 g/Cm³

120 g Cm³

1.25g/Cm³

122. 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:

112 cm³

224 cm³

22400 cm³

1.008 g

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

Heat energy

Sound energy

Magnetic energy

Electrical energy

124. Molton NaCl conducts electricity due to the presence of

Free electrons

Free molecules

Atoms of Na and Cl.

Free ions

125. The unit of specific conductivity is

Ohm cm¯²

Ohm¯¹ cm

Ohm¯¹ cm¯¹

Ohm cm¯¹

Page 6 of 8

126. Mole fraction of pure water is

Slightly less than one

Slightly greater than one

None of these

Exactly equal to one

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

None

128. Colligative properties are the properties of

Concentration solutions behave as nearly non – ideal solutions

Both a and b

Dilute solution which behave as nearly ideal solution

Neither a nor b

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

Equal to that of ethanol

More than that of H₂O

Equal to that of water

Less than that of water

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

One gm. Equivalent weight

None of these

One gm. atomic weight

Electrochemical equivalent

131. A redox reaction involves

Ion combination reaction

Proton transfer

A reaction in a solution

Electron transfer

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

96500

48250

193000

10000

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

O₂, SO₂

O₂, Na

None of these

O₂,H₂

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

2 ampere

1 coulomb

1 faraday

1 ampere

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

40 ml

10 ml

80 ml

20 ml

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

0.01

100

0.001

137. Secondary cell is

Rechargeable

Electrolytic cell

Daniel cell

Non rechargeable

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

0.2

0.0196

0.01

0.1

139. The art of electroplating was given by

Edison

Thomas Gradam

Faraday

Brugan

140. 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?

8.14 M

4.18 M

18 M

18.4 M

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

Remove adsorbed oxygen from electrode surfaces

Generate heat

Produce high purity water

Create potential difference between two electrodes

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

106.15 kJ

53.07 kJ

212.3 kJ

175.4 kJ

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

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

1.5

145. 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

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

0.1 M BaCl₂

0.1 M Glucose

0.1 M NaCl

0.1 M Sucrose

147. 8 g of NaOh is dissolved in 500 cm³ of solution, its molarity is:

0.4 M

0.2 M

0.8 M

0.04 M

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

Galvanization

Electrolysis

Cathodic protection

Photo electrolysis

149. 0.5 M of H₂SO₄ is diluted from 1 liter to 10 liter, normality of resulting solution is

1 N

0.1N

10 N

11 N

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

Both

Oxidation

Reduction

Page 7 of 8

151. Camphor is often used in molecular mass determination because

It has a very high cryoscopic constant

It is volatile

It is readily available

It is solvent for organic substances

152. Azeotropic mixture of HCl and water has

22.2% HCl

36% HCl

48% HCl

20.2% HCl

153. Oxidation state of hydrogen in CaH₂ is

-1

-2

154. The degree of dissociation of weak electrolyte increases as

Dilution decreases

Dilution increases

None

Pressure increases

155. When common salt is dissolved in water

Any possibility

B.P of water decrease

B.P of water increase

B.P of water remain constant

156. 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

1.0

1.5

2.0

0.5

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

NH₄OH

NaOH

Ca(OH)₂

KOH

158. Chemical used in salt bridge is

KCI

KOH

KNO3

KBr

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

Fuel cell

Electrolytic cell

Galvanic cell

Dry cell

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

Na and Hg

Pt and graphite only

Na, Pt and graphite

Na and S only

161. 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

12.8 g

3.2 g

6.4 g

2.3 g

162. In an electrolytic cell current flows

From anode to cathode inside the cell

From cathode to anode inside the cell

From anode to cathode in an outer circuit

From cathode to anode in outer circuit

163. 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)

0.333

3.33

33.3

0.0033

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

Making leather

Electroplating

Rust removal

Manufacture of bleach

165. Reduction always occurs

At cathode

None of these

At anode

Both A and B

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

0.0186

1.86

0.521

0.0521

167. 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

9 N

2 N

3 N

1 N

168. 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

Hg is more inert than Pt

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

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

169. 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

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

Galvanic cell

Daniel cell

Electrolytic cell

Fuel cell

171. 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

108 g

10.8 g

1.08 g

21.6 g

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

1 – 2 α

1 + 2 α

1 – α

1 + α

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

Electrons flow from cathode to anode through the external battery

Electrons flow cathode to anode within the electrolytic solution

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

None of these

174. 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

0.05 M

0.15 M

0.1 M

0.2 M

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

Na → Na⁺ + e–

Na⁺ + e– → Na

Br₂ + 2e – → 2Br –

2Br– → Br₂ + 2e –

Page 8 of 8

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

∆ G = +ve, ∆ E = 0

∆ G = 0, ∆E = 0

∆ G = -ve

∆ G = -ve, ∆ E = 0

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

760 mm of Hg

2.5 atom

Slightly more than 1 atom

750 torr

178. 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

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

Does not change

Increases rapidly

Drops to zero

Increases gradually

180. Salt bridge transfers

Anions

Solvent particles

Electrons

Current

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

Chloroform

Molten NaCl

Pure distilled water

Dilute solution of glucose

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

780 mm of Hg

760 mm of Hg

750 mm of Hg

800 mm of Hg

183. Salt bridge transfers

Anion

Electrons

Ions

Current

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

8 N

4 N

6 N

2 N

185. The reference electrode is made by using

CuSO₄

Hg₂Cl₂

HgCl₂

ZnCl₂

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

Arrhenius law

Raoult’s law

Ostwald’s law

Henry’s law

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

Ag⁺

I₂

Pb²⁺

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

Elevation in boiling point

Ionic concentration

Flow of solvent from a concentrated to a dilute solution

Diffusion rate of the solute

189. 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

B > C > A

A > B > C

C > B > A

A > C > B

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

10,000 s

30 s

10 s

30,000 s

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

Reduced

Oxidized

Hydrolyzed

Precipitated

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

None of these

Na⁺

Cl¯

Both Na⁺ and CI¯

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Malik TahirLast Updated: October 14, 2025

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