Home/Chemistry Mcqs/Chemistry Electro Chemistry Online Mcqs Test

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

Raoult’s law

Ostwald’s dilution law

Distribution law

Henry’s law

2. Strong reducing agents have

None of these

Greater negative value of standard reduction potential

Greater positive value of standard reduction potential

Lesser positive value of standard reduction potential

3. Density of H₂SO₄ in lead accumulator is

120 g Cm³

1.25g/Cm³

1.2 g/Cm³

1.15 g/Cm³

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

0.05

0.5

2.05

0.25

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

Electrical energy

None of these

Chemical energy

Heat energy

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

Heat energy

Sound energy

Electrical energy

Magnetic energy

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

Boiling point

Inversion point

Sublimation point

Melting point

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

Gains electrons

pH is changed

Acts as a catalyst

Loses electrons

9. Temperature for standard electrode potential is

310 K

25 C°

300 K

273 K

10. 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

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

12. 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

4 C

240 C

120 C

20 C

13. The best reducing agent is

F¯

Cl¯

I¯

Br¯

14. Corrosion reactions are

Spontaneous acid–base reactions

None of these

Non-spontaneous redox reactions

Spontaneous redox reactions

15. Maximum freezing point falls in

Water

Naphthalene

Camphor

Benzene

16. The Vant Hoff factor (i) accounts for

The extent of dissociation of solute

The extent of dissolution of solute

The degree of decomposition of solution

Degree of solubilization of solute

17. Oxidation state of hydrogen in CaH₂ is

-1

-2

18. 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 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 Cu²+/Cu is lower than that of Li⁺/Li

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

Boric acid

Phosphorus acid

Sulphuric acid

Nitric acid

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

0.2

0.0196

0.01

0.1

21. Salt bridge transfers

Current

Ions

Electrons

Anion

22. 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

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

10000

96500

193000

48250

24. Chemical used in salt bridge is

KCI

KNO3

KOH

KBr

25. 8 g of NaOh is dissolved in 500 cm³ of solution, its molarity is:

0.04 M

0.4 M

0.8 M

0.2 M

Page 2 of 8

26. Vant Hoff’s factor of Ca(NO₃)₂ is

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

Induction

Electroplating

Electrolysis

Conduction

28. Colligative properties are the properties of

Both a and b

Concentration solutions behave as nearly non – ideal solutions

Neither a nor b

Dilute solution which behave as nearly ideal solution

29. Best way to prevent rusting iron is by

Putting it in saline water

Both of these

Making iron cathode

None of these

30. The unit of specific conductivity is

Ohm cm¯²

Ohm¯¹ cm¯¹

Ohm¯¹ cm

Ohm cm¯¹

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

7.20

4.10

3.12

0.217

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

Microgram percent

Parts per million

Gram per million

Milligram percent

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

40 ml

20 ml

80 ml

10 ml

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

CH₃ CooNH₄

NaCl

Na₂SO₄

NH₄Cl

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

Drops to zero

Decrease rapidly

Does not change

Decreases slowly

36. 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

1.25

None of these

2.5

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

1 g

4 g

2 g

5 g

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

0.521

1.86

0.0186

0.0521

39. Standard hydrogen electrode has an arbitrarily fixed potential

1.00 volt

0.10 volt

None of these

0.00 volt

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

Oxidation

Reduction

Both

Reduction

41. Camphor is often used in molecular mass determination because

It is volatile

It is solvent for organic substances

It is readily available

It has a very high cryoscopic constant

42. 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)

0.222 V

0.176 V

0.399 V

0.281 V

43. Reduction always occurs

At anode

At cathode

None of these

Both A and B

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

5.51

6.1

1.32

5.65

45. The reference electrode is made by using

Hg₂Cl₂

ZnCl₂

HgCl₂

CuSO₄

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

0.5 molal

0.1 molal

1.1 molal

1 molal

47. During a redox reaction, an oxidizing agent

Gains electrons

Loses electrons

Is oxidized

Is hydrolysed

48. 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

3.2 g

2.3 g

6.4 g

12.8 g

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

Viscosity

Refractive index

Osmotic pressure

Surface tension

50. The degree of dissociation of weak electrolyte increases as

Dilution increases

Dilution decreases

None

Pressure increases

Page 3 of 8

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

30 s

10 s

30,000 s

10,000 s

52. 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

53. Stronger the oxidizing agent, greater is the

Oxidation potential

Redox potential

e.m.f of cell

Reduction potential

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

None

Sum of reduction and oxidation potentials

Lesser

Greater

55. 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

0.142 cm¯¹

1.12 cm¯¹

0.66 cm¯¹

0.918 cm¯¹

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

None of these

Cl¯

Na⁺

Both Na⁺ and CI¯

57. 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 water decreases by the addition of ethanol

Boiling point of pure benzene increases by the addition of toluene

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

58. Molton NaCl conducts electricity due to the presence of

Free molecules

Free ions

Atoms of Na and Cl.

Free electrons

59. 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

60. 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

61. In alkaline battery anode is made up of

AgO₂

Cadmium

MnO₂

62. 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

63. Decrease in oxidation number is called

Redox

Oxidation

All of these

Reduction

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

1 f

1 N

1 M

2 M

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

Manufacture of bleach

Electroplating

Rust removal

Making leather

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

Very low ionization potential values

Very high negative values reduction potential

Very high positive value of reduction potential

Reduction potentials are negative

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

MgCl₂

KCl

BaCl₂

NaCl

68. 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

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

0.512

0.0512

0.186

0.80

70. The solubility of a gas in water depends upon

Pressure of the gas

Temperature

Nature of the gas

All of these

71. In electrolytic cell, electricity in carried out by

All

Spontaneous reaction

Non-spontaneous reaction

Neutralization

72. Half cells are interconnected through

Electric circuit

No connection exists

Salt Bridge

Wire

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

None

74. An electrolyte

Forms complex ions in solution

Gives ions only when electricity is passed

Possesses ions even in solid state

Gives ions only when dissolved in water

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

Pb²⁺

Ag⁺

I₂

Page 4 of 8

76. Oxidation in a chemical reaction involves

Both are possible

Decrease in oxidation number

Increase in oxidation number of all the elements on reactant side

Increase in oxidation number

77. The conductivity of strong electrolyte

Increases on dilution slightly

Does not change on dilution

Depends on density of electrolyte itself.

Decreases on dilution

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

0.01

0.0196

0.2

0.1

79. Reaction takes place at anode is

Reduction

Hydrolysis

Ionization

Oxidation

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

∆ G = -ve

∆ G = -ve, ∆ E = 0

∆ G = +ve, ∆ E = 0

∆ G = 0, ∆E = 0

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

Less than that of water

More than that of H₂O

Equal to that of water

Equal to that of ethanol

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

Both oxidation and reduction

Oxidation

Reduction

Neither oxidation and reduction

83. The depression of freezing point is directly proportional to

Molarity of the solution

Molarity of the solvent

Molality of the solution

Mole fraction of the solution

84. 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

A > B > C

B > C > A

C > B > A

85. Solution with same osmotic pressures are called

Hypertonic

Normal

Hypotonic

Isotonic

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

One gm. Equivalent weight

One gm. atomic weight

Electrochemical equivalent

None of these

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

1.5

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

176 S cm² mol¯¹

278 S cm² mol¯¹

302 S cm² mol¯¹

128 S cm² mol¯¹

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

1 molar

1 molal

1 normal

All

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

+ 1.17 V

– 0.35 V

– 1.17 V

+ 0.35

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

14.25%

13.1%

9.09%

11.2%

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

93. 96500 C of electricity liberates from CuSO₄ solution

100 g of Cu

63.5 g of Cu

31.75 g of Cu

96500 g of CU

94. 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 and S only

Pt and graphite only

Na, Pt and graphite

95. Choose the best reducing agent among the following

Cl¯¹

I¯¹

F¯¹

Br¯¹

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

Arrhenius law

Henry’s law

Raoult’s law

Ostwald’s law

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

O₂, SO₂

O₂,H₂

O₂, Na

None of these

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

53.07 kJ

212.3 kJ

175.4 kJ

106.15 kJ

99. 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

0.2 M

0.15 M

0.1 M

0.05 M

100. The art of electroplating was given by

Brugan

Thomas Gradam

Edison

Faraday

Page 5 of 8

101. 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

1 N

3 N

102. 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

72 torr

20 torr

140 torr

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

0.1 N HCl

0.1 N NaCl

Glass

Graphite

104. Which has maximum oxidation number

105. 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

0.30

0.25

0.40

0.35

106. 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

0.2

0.9

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

510 sec

102 sec

642 sec

12157.48 sec

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

Weak acid and its salt of weak base

A strong acid and its salt of a strong base

Strong acid and its salt of weak base

Weak acid and its salt of strong base

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

1.15 cm¯³

1.81 cm¯³

1.25 cm¯³

2.15 cm¯³

110. 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

0.001

100

111. Which of the following is a strong electrolyte?

HCN

Ca(NO₃)₂

NH₄OH

CH₃COOH

112. Specific conductivity of a solution

Remains unchanged with dilution

Increases with dilution

Depends on mass of electrolyte

Decreases with dilution

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

An electrolytic cell

A galvanic cell

A voltaic cell

A chemical cell

114. Secondary cell is

Non rechargeable

Rechargeable

Electrolytic cell

Daniel cell

115. 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?

31.8 gm

12.7 gm

63.5 gm

15.9 gm

116. In an electrolytic cell current flows

From cathode to anode in outer circuit

From anode to cathode in an outer circuit

From cathode to anode inside the cell

From anode to cathode inside the cell

117. 96500 C electricity is passed through CuSO₄. The amount of copper precipitated is

2.00 mole

0.5 mole

1.0 mole

0.25 mole

118. Mole fraction of pure water is

Slightly greater than one

None of these

Slightly less than one

Exactly equal to one

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

Fractional distillation

Distillation

Vacuum distillation

None of these

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

Supersaturated

Saturated

Unsaturated

Ideal

121. Electricity in voltaic cell is produced due to

Neutralization

B + C

Oxidation

Reduction

122. 0.5 M of H₂SO₄ is diluted from 1 liter to 10 liter, normality of resulting solution is

11 N

10 N

1 N

0.1N

123. 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

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

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

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

Standard electrode potential

Electric change

Electroplating

Ionization potential

125. Salt bridge transfers

Anions

Solvent particles

Electrons

Current

Page 6 of 8

126. 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

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

Photo electrolysis

Galvanization

Electrolysis

Cathodic protection

128. 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 is denser

Gold has higher reduction potential then iron

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

Hg₂Cl₂

CuSO₄

HgCl₂

ZnCl₂

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

Electrode

Anode

Cathode

None of these

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

Electrons flow from cathode to anode through the external battery

None of these

Electrons flow cathode to anode within the electrolytic solution

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

132. In a Galvanic cell, the electrons flow from

Anode to cathode through the solution

Cathode to anode through the external circuit

Anode to cathode through the external circuit

Cathode to anode through the solution

133. 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?

4.18 M

18.4 M

18 M

8.14 M

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

Generate heat

Remove adsorbed oxygen from electrode surfaces

Create potential difference between two electrodes

Produce high purity water

135. Which of the following statements is FALSE?

All electrochemical reactions involve the transfer of electrons

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.

Reduction occurs at cathode

136. 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

137. Molarity of water is

55.5

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

45.1

39.6

40.5

42.7

139. 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

S m mol¯¹

S² m² mol

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

Flow of solvent from a concentrated to a dilute solution

Elevation in boiling point

Ionic concentration

Diffusion rate of the solute

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

In middle

Lower

Higher

Not particular

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

0.54 g

1.08 g

2.16 g

0.27 g

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

58.5g NaCl/100ml

5.58g NaCl/100m

20g NaCl/100ml

10.0g NaCl/100ml

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

0.1 M NaCl

0.1 M Sucrose

0.1 M BaCl₂

0.1 M Glucose

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

10 g

2 g

20 g

1 g

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

None of these

Electrorefining

Electroplating

Both A and B

147. 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

2 N

0.2 N

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

Increases gradually

Does not change

Drops to zero

Increases rapidly

149. 18g of glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to

5.1

1/51

1/5

150. 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

0.75

0.20

0.80

0.60

Page 7 of 8

151. A redox reaction involves

Ion combination reaction

Electron transfer

Proton transfer

A reaction in a solution

152. Alkaline battery has a voltage of

1.5V

3.5V

4.5V

2.5V

153. In alkaline battery the anode is made up of

Cadmium

AgO2

MnO2

154. Pure water does not conduct electricity because it

Is neutral

Is readily decomposed

Is almost unionized

Has low boiling point

155. Cathode provides electrons to

Neutral atom

Does not provide any electron

+Ve ion

-Ve ion

156. Corrosion is basically a

Interaction

Altered reaction in presence of H₂O

Electrochemical phenomenon

Union between two light metals and a heavy metal

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

12.1 atm

1.21 atm

24.6 atm

2.46 atm

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

2 ampere

1 ampere

1 coulomb

1 faraday

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

F₂O

Cl₂O

Na₂O₂

Na₂O

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

2 to 5

0 to –3

1 to 5

0 to 5.

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

Chlorine

Chloride

Hydrogen

Oxygen

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

Dry cell

Electrolytic cell

Fuel cell

Galvanic cell

163. 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

164. Units of molarity are

Mol/lit

Kg/lit

None of these

Gm/lit

165. Potential of Zn is called

It has not potential

Redox

Reduction

Oxidation

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

Dilute solution of glucose

Molten NaCl

Pure distilled water

Chloroform

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

NH₄OH

Ca(OH)₂

KOH

NaOH

168. If liquids A and B form an ideal solution

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

The entropy of mixing is zero

The free energy of mixing is zero

The enthalpy of mixing is zero

169. Azeotropic mixture of HCl and water has

36% HCl

22.2% HCl

48% HCl

20.2% HCl

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

Equal to the total volume of the components

None of these

Slightly more than the total volume of the components

Slightly less than the total volume of the components

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

Fuel cell

Daniel cell

Electrolytic cell

Galvanic cell

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

8 N

6 N

2 N

4 N

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

1.0

0.5

2.0

1.5

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

175. Density of H₂SO₄ in lead accumulator is

1.25g/cm3

1.15g/cm3

1.20g/cm3

1.3g/cm3

Page 8 of 8

176. Voltaic cell can be recharged by

By replacing external circuit with external source of electricity

By addition of fresh solution

By removal of solution

By heating it

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

Na⁺ + e– → Na

2Br– → Br₂ + 2e –

Na → Na⁺ + e–

Br₂ + 2e – → 2Br –

178. 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

179. 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)

33.3

0.0033

0.333

3.33

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

60 g

6 g

40 g

4 g

181. Oxidation number of carbon in NaHCO₃ is

-6

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

H₃PO₂

H₄P₃O₇

H₃PO₃

H₃PO₄

183. Electrode potential of Zn is

Reduction

Oxidation

Depends on the nature of the coupled electrode

Oxidation-reduction

184. In a chemical reaction, oxidation process involves

Oxidation number neither increases nor decreases

Increase in oxidation number of the elements in reactants

Decrease in oxidation number of element

Increase in oxidation number of element

185. 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)₄Cl₂]Cl₂

[Pt(NH₃)₄Cl]Cl₃

[Pt(NH₃)₄Cl₄]

[Pt(NH₃)₄Cl₃]Cl

186. 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

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

Hydrolyzed

Oxidized

Precipitated

Reduced

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

Standard oxidation potential

Standard reduction potential

Cell voltage

Ionization potential

189. Pick out the wrong statement. In electrochemical cell

Cathode is regarded as negative electrode

Electrons are released at anode

Chemical energy is converted into electrical energy

Salt bridge maintains the electrical neutrality of the solution

190. What are the ions present in water?

H2O

H and OH

H+ and OH-

H2 and O

191. Metals usually conduct electricity because

Metals are decomposed by current

In metals the ions are free to more

Metals have high resistance

They are mobile electrons in the metallic structure

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

Slightly more than 1 atom

750 torr

760 mm of Hg

2.5 atom

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Malik TahirLast Updated: October 14, 2025

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