10th Class Chemistry Chapter 3 TestELECTROCHEMISTRY

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. Which catalyst is commonly used in the porous carbon electrodes of a fuel cell?

   1. Copper

   2. Zinc

   3. Platinum

   4. Iron

2. During electrolysis, the molten lead is maintained in a heated crucible above:

   1. 100°C

   2. 300°C

   3. 500°C

   4. 1000°C

3. During oxidation, the oxidation number or oxidation state of an element always:

   1. Decreases

   2. Increases

   3. Remains zero

   4. Becomes negative

4. Oxidation is a process in which:

   1. Oxygen is removed

   2. Hydrogen is added

   3. Oxygen is added or hydrogen is removed

   4. Electrons are gained

5. Regardless of the electrode type, the reaction at the cathode always involves:

   1. Oxidation of water

   2. Evolution of oxygen gas

   3. Reduction of copper ions

   4. Formation of sulphate gas

6. Acidified KMnO₄ oxidizes oxalic acid into:

   1. Carbon monoxide

   2. Carbon dioxide

   3. Carbonic acid

   4. Methane

7. The element calcium is present in Group II of the periodic table, so its principal oxidation number is:

   1. 

   2. 

   3. 

   4. 

8. Before electroplating, the article to be electroplated is first cleaned with:

   1. Sand

   2. Oil

   3. Alcohol

   4. Wax

9. In oxalic acid, the initial oxidation number of each carbon atom is:

   1. +2

   2. +3

   3. +4

   4. +5

10. When an aqueous solution of copper (II) sulfate is electrolyzed with inert electrodes, what is deposited at the cathode?

    1. Sulfur dioxide

    2. Copper metal

    3. Hydrogen gas

    4. Oxygen gas