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

CuSO₄

Hg₂Cl₂

HgCl₂

ZnCl₂

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

Electroplating

Both A and B

Electrorefining

None of these

3. What are the ions present in water?

H2O

H2 and O

H and OH

H+ and OH-

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

∆ G = -ve

∆ G = 0, ∆E = 0

∆ G = -ve, ∆ E = 0

∆ G = +ve, ∆ E = 0

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

Ideal

Supersaturated

Unsaturated

Saturated

6. 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

20 torr

72 torr

140 torr

68 torr

7. 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

56 cm³

11.2 cm³

5.6 cm³

550 cm³

8. 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

9. Oxidation number of carbon in NaHCO₃ is

-6

10. Potential of Zn is called

Redox

Reduction

It has not potential

Oxidation

11. 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

10 s

30,000 s

30 s

12. 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

0.281 V

0.399 V

0.222 V

13. 96500 C of electricity liberates from CuSO₄ solution

31.75 g of Cu

96500 g of CU

100 g of Cu

63.5 g of Cu

14. Maximum freezing point falls in

Water

Benzene

Camphor

Naphthalene

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

Milligram percent

Parts per million

Microgram percent

Gram per million

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

None of these

Electrode

Anode

Cathode

17. 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)₄Cl]Cl₃

[Pt(NH₃)₄Cl₂]Cl₂

[Pt(NH₃)₄Cl₃]Cl

18. Strong reducing agents have

Greater positive value of standard reduction potential

Lesser positive value of standard reduction potential

Greater negative value of standard reduction potential

None of these

19. Salt bridge transfers

Solvent particles

Current

Electrons

Anions

20. Alkaline battery has a voltage of

2.5V

4.5V

1.5V

3.5V

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

Hydrogen

Chlorine

Oxygen

Chloride

22. Standard hydrogen electrode has an arbitrarily fixed potential

0.10 volt

1.00 volt

None of these

0.00 volt

23. In a Galvanic cell

Chemical energy is converted into heat

Electrical energy is converted into heat

Chemical energy is converted into electricity

Electrical energy is converted into chemical energy

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

Melting point

Sublimation point

Boiling point

Inversion point

25. 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

Page 2 of 8

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

Oxidation

Reduction

Both oxidation and reduction

Neither oxidation and reduction

27. Temperature for standard electrode potential is

300 K

310 K

273 K

25 C°

28. 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

0.5 molal

1 molal

29. 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

31.8 gm

63.5 gm

15.9 gm

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

Cell voltage

Ionization potential

Standard oxidation potential

Standard reduction potential

31. Camphor is often used in molecular mass determination because

It is volatile

It has a very high cryoscopic constant

It is solvent for organic substances

It is readily available

32. 0.5 M of H₂SO₄ is diluted from 1 liter to 10 liter, normality of resulting solution is

0.1N

10 N

1 N

11 N

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

Cl₂O

Na₂O

Na₂O₂

F₂O

34. 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 + α

1 + 2 α

1 – 2 α

35. 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

278 S cm² mol¯¹

128 S cm² mol¯¹

176 S cm² mol¯¹

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

None

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

Li is smaller in size as compared to Cu

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

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

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

More than that of H₂O

Equal to that of water

Equal to that of ethanol

Less than that of water

39. Best way to prevent rusting iron is by

Making iron cathode

None of these

Both of these

Putting it in saline water

40. Oxidation state of hydrogen in CaH₂ is

-1

-2

41. A redox reaction involves

Proton transfer

Ion combination reaction

Electron transfer

A reaction in a solution

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

0.1 N NaCl

0.1 N HCl

Glass

Graphite

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

Raoult’s law

Ostwald’s law

Henry’s law

Arrhenius law

44. 8 g of NaOh is dissolved in 500 cm³ of solution, its molarity is:

0.8 M

0.04 M

0.2 M

0.4 M

45. 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

46. 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

47. Chemical used in salt bridge is

KNO3

KOH

KCI

KBr

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

All

1 molar

1 molal

1 normal

49. 2.5 faradays of electricity is passed through solution of CuSO₄. The number of gram equivalents of copper deposited on the cathode would be

2.5

1.25

None of these

1 2

50. 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

Page 3 of 8

51. If liquids A and B form an ideal solution

The enthalpy of mixing is zero

The entropy of mixing is zero

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

The free energy of mixing is zero

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

40 ml

80 ml

10 ml

20 ml

53. 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

4.18 M

18.4 M

8.14 M

54. In alkaline battery the anode is made up of

Cadmium

AgO2

MnO2

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

Slightly more than 1 atom

760 mm of Hg

750 torr

2.5 atom

56. 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

Reduction potentials are negative

Very high positive value of reduction potential

Very high negative values reduction potential

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

40 g

60 g

6 g

4 g

58. 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

20 g

1 g

2 g

59. Which of the following is a strong electrolyte?

NH₄OH

HCN

CH₃COOH

Ca(NO₃)₂

60. Specific conductivity of a solution

Remains unchanged with dilution

Increases with dilution

Depends on mass of electrolyte

Decreases with dilution

61. 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 10³

1.06 x 10²

1.06 x 10⁴

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

Standard electrode potential

Electroplating

Electric change

Ionization potential

63. Corrosion is basically a

Interaction

Union between two light metals and a heavy metal

Electrochemical phenomenon

Altered reaction in presence of H₂O

64. 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

S m² mol¯¹

S² m² mol

S² m² mol¯²

S m mol¯¹

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

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

6.1

5.65

1.32

5.51

67. Mole fraction of pure water is

Slightly less than one

Slightly greater than one

None of these

Exactly equal to one

68. The degree of dissociation of weak electrolyte increases as

Dilution decreases

Dilution increases

None

Pressure increases

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

2.0

1.0

1.5

0.5

70. Density of H₂SO₄ in lead accumulator is

1.15g/cm3

1.25g/cm3

1.20g/cm3

1.3g/cm3

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

2 ampere

1 faraday

1 ampere

1 coulomb

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

1 M

1 f

1 N

2 M

73. Solution with same osmotic pressures are called

Hypotonic

Hypertonic

Normal

Isotonic

74. During a redox reaction, an oxidizing agent

Is oxidized

Is hydrolysed

Loses electrons

Gains electrons

75. 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

Page 4 of 8

76. In an electrolytic cell current flows

From cathode to anode inside the cell

From cathode to anode in outer circuit

From anode to cathode inside the cell

From anode to cathode in an outer circuit

77. Decrease in oxidation number is called

Redox

All of these

Oxidation

Reduction

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

Galvanic cell

Electrolytic cell

Fuel cell

Daniel cell

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

Dry cell

Electrolytic cell

Fuel cell

Galvanic cell

80. Molton NaCl conducts electricity due to the presence of

Atoms of Na and Cl.

Free ions

Free electrons

Free molecules

81. 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

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

Nitric acid

Boric acid

Phosphorus acid

Sulphuric acid

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

Produce high purity water

Remove adsorbed oxygen from electrode surfaces

Create potential difference between two electrodes

Generate heat

84. 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 strong base

Weak acid and its salt of weak base

Strong acid and its salt of weak base

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

Fractional distillation

None of these

Distillation

Vacuum distillation

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

Manufacture of bleach

Rust removal

Electroplating

Making leather

87. Corrosion reactions are

Non-spontaneous redox reactions

None of these

Spontaneous acid–base reactions

Spontaneous redox reactions

88. Azeotropic mixture of HCl and water has

48% HCl

22.2% HCl

20.2% HCl

36% HCl

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

H₃PO₄

H₃PO₃

H₄P₃O₇

H₃PO₂

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

0.217

7.20

4.10

3.12

91. Units of molarity are

Gm/lit

None of these

Kg/lit

Mol/lit

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

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

0.1 M Sucrose

0.1 M NaCl

0.1 M Glucose

0.1 M BaCl₂

94. Reduction always occurs

None of these

At anode

At cathode

Both A and B

95. 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

0.0521

0.521

96. Reaction takes place at anode is

Reduction

Oxidation

Hydrolysis

Ionization

97. 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

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

Reduction

Both

Reduction

Oxidation

99. 18g of glucose is dissolved in 90g of water. The relative lowering of vapour pressure is equal to

1/5

5.1

1/51

100. In electrolytic cell, electricity in carried out by

Neutralization

Non-spontaneous reaction

Spontaneous reaction

All

Page 5 of 8

101. 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

102. Which has maximum oxidation number

103. Salt bridge transfers

Current

Anion

Ions

Electrons

104. 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

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

Ca(OH)₂

KOH

NaOH

NH₄OH

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

12.1 atm

1.21 atm

24.6 atm

2.46 atm

107. An electrolyte

Possesses ions even in solid state

Gives ions only when dissolved in water

Gives ions only when electricity is passed

Forms complex ions in solution

108. 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

20 C

240 C

120 C

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

+ 0.35

– 0.35 V

– 1.17 V

+ 1.17 V

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

Photo electrolysis

Galvanization

Cathodic protection

Electrolysis

111. Pick out the wrong statement. In electrochemical cell

Salt bridge maintains the electrical neutrality of the solution

Cathode is regarded as negative electrode

Electrons are released at anode

Chemical energy is converted into electrical energy

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

Decreases slowly

Does not change

Drops to zero

Decrease rapidly

113. 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

2.0 x 10¹¹

1.0 x 10²

1.0 x 10¹⁰

114. The reference electrode is made by using

CuSO₄

HgCl₂

Hg₂Cl₂

ZnCl₂

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

0.2

0.6

0.9

0.3

116. 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

117. 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

0.80

0.20

0.75

0.60

118. In a Galvanic cell, the electrons flow from

Cathode to anode through the solution

Anode to cathode through the external circuit

Cathode to anode through the external circuit

Anode to cathode through the solution

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

120. 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

21.6 g

10.8 g

1.08 g

121. Stronger the oxidizing agent, greater is the

Reduction potential

e.m.f of cell

Redox potential

Oxidation potential

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

A galvanic cell

A voltaic cell

A chemical cell

An electrolytic cell

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

760 mm of Hg

800 mm of Hg

780 mm of Hg

750 mm of Hg

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

11.2%

9.09%

14.25%

13.1%

125. 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

Page 6 of 8

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

0 to –3

1 to 5

2 to 5

0 to 5.

127. Metals usually conduct electricity because

They are mobile electrons in the metallic structure

Metals are decomposed by current

In metals the ions are free to more

Metals have high resistance

128. In a chemical reaction, oxidation process involves

Decrease in oxidation number of element

Increase in oxidation number of the elements in reactants

Oxidation number neither increases nor decreases

Increase in oxidation number of element

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

1.81 cm¯³

2.15 cm¯³

1.15 cm¯³

1.25 cm¯³

130. 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

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

Higher

Lower

In middle

Not particular

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

Oxidized

Reduced

Hydrolyzed

Precipitated

133. 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

134. In alkaline battery anode is made up of

Cadmium

MnO₂

AgO₂

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

Gold is denser

Gold has lower reduction potential then iron

Gold has higher reduction potential then iron

Iron rusts

136. The unit of specific conductivity is

Ohm cm¯¹

Ohm cm¯²

Ohm¯¹ cm¯¹

Ohm¯¹ cm

137. 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)

0.0033

33.3

3.33

0.333

138. The best reducing agent is

Br¯

Cl¯

F¯

I¯

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

Na and S only

Na and Hg

Pt and graphite only

Na, Pt and graphite

140. 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

C > B > A

A > C > B

A > B > C

B > C > A

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

Hg is more inert than Pt

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

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

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

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

53.07 kJ

175.4 kJ

106.15 kJ

212.3 kJ

143. Pure water does not conduct electricity because it

Has low boiling point

Is almost unionized

Is neutral

Is readily decomposed

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

Viscosity

Refractive index

Surface tension

Osmotic pressure

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

Pb²⁺

I₂

Ag⁺

146. Secondary cell is

Electrolytic cell

Daniel cell

Non rechargeable

Rechargeable

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

2.16 g

0.27 g

0.54 g

1.08 g

148. 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

149. 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

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

Diffusion rate of the solute

Flow of solvent from a concentrated to a dilute solution

Ionic concentration

Elevation in boiling point

Page 7 of 8

151. 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

152. Molarity of water is

55.5

153. 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

0.2 N

4 N

2 N

0.4 N

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

Molten NaCl

Dilute solution of glucose

Pure distilled water

Chloroform

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

Na₂SO₄

NH₄Cl

NaCl

CH₃ CooNH₄

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

58.5g NaCl/100ml

5.58g NaCl/100m

10.0g NaCl/100ml

20g NaCl/100ml

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

Electrochemical equivalent

None of these

One gm. Equivalent weight

One gm. atomic weight

158. 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

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

0.0196

0.1

0.01

0.2

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

45.1

42.7

40.5

39.6

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

193000

96500

10000

48250

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

12157.48 sec

642 sec

510 sec

102 sec

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

Slightly more than the total volume of the components

Equal to the total volume of the components

None of these

Slightly less than the total volume of the components

164. The conductivity of strong electrolyte

Increases on dilution slightly

Does not change on dilution

Decreases on dilution

Depends on density of electrolyte itself.

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

166. The art of electroplating was given by

Faraday

Edison

Thomas Gradam

Brugan

167. Which of the following statements is FALSE?

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

Reduction occurs at cathode

All electrochemical reactions involve the transfer of electrons

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

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

Chemical energy

None of these

Heat energy

Electrical energy

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

Na → Na⁺ + e–

2Br– → Br₂ + 2e –

Br₂ + 2e – → 2Br –

Na⁺ + e– → Na

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

1.5

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

Increases gradually

Does not change

Increases rapidly

Drops to zero

172. Electrode potential of Zn is

Depends on the nature of the coupled electrode

Reduction

Oxidation-reduction

Oxidation

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

Greater

None

Sum of reduction and oxidation potentials

Lesser

174. The solubility of a gas in water depends upon

Temperature

All of these

Nature of the gas

Pressure of the gas

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

2 g

4 g

1 g

5 g

Page 8 of 8

176. Colligative properties are the properties of

Neither a nor b

Both a and b

Concentration solutions behave as nearly non – ideal solutions

Dilute solution which behave as nearly ideal solution

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

Na⁺

Both Na⁺ and CI¯

None of these

Cl¯

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:

112 cm³

224 cm³

22400 cm³

1.008 g

179. Cathode provides electrons to

Neutral atom

+Ve ion

Does not provide any electron

-Ve ion

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

KCl

MgCl₂

BaCl₂

NaCl

181. Half cells are interconnected through

No connection exists

Salt Bridge

Wire

Electric circuit

182. Electricity in voltaic cell is produced due to

Reduction

B + C

Oxidation

Neutralization

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

Gains electrons

pH is changed

Loses electrons

Acts as a catalyst

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

Sound energy

Heat energy

Magnetic energy

Electrical energy

185. Density of H₂SO₄ in lead accumulator is

1.25g/Cm³

120 g Cm³

1.15 g/Cm³

1.2 g/Cm³

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

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

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 benzene decreases by the addition of naphthalene

187. 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

0.30

0.35

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

None of these

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

Electrons flow cathode to anode within the electrolytic solution

Electrons flow from cathode to anode through the external battery

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

Sufficient date not given

1.86 c°

18.6 c°

0.186 c°

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

None of these

O₂, Na

O₂,H₂

O₂, SO₂

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

2.05

0.5

0.05

0.25

192. Choose the best reducing agent among the following

I¯¹

F¯¹

Br¯¹

Cl¯¹

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Malik TahirLast Updated: October 14, 2025

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