Chapter 7: Electrochemistry

Chapter 7 explains the chemical changes that occur when electricity passes through substances and the role of electrochemical processes in daily life. It covers electrolysis, electrolytes, galvanic cells, and practical applications like electroplating. These MCQs test the understanding of core concepts and problem-solving related to electrochemistry.

1. What is electrochemistry?

  • A. Study of heat in chemical reactions
  • B. Study of the relationship between electricity and chemical changes ✅
  • C. Study of acids and bases
  • D. Study of energy transfer
Explanation: Electrochemistry focuses on chemical reactions involving the flow of electric current.

2. Which substance allows electric current to pass through by ion movement?

  • A. Non-electrolyte
  • B. Electrolyte ✅
  • C. Semiconductor
  • D. Insulator
Explanation: Electrolytes produce ions in solution or molten state, allowing current flow.

3. In electrolysis of water, hydrogen gas is released at the:

  • A. Anode
  • B. Cathode ✅
  • C. Both electrodes
  • D. None
Explanation: At the cathode, reduction takes place, releasing hydrogen gas from water electrolysis.

4. What is electroplating?

  • A. Coating with paint
  • B. Coating an object with a thin layer of metal using electricity ✅
  • C. Melting metals together
  • D. Painting with metallic colors
Explanation: Electroplating deposits a thin layer of metal on an object via electrolysis.

5. Which of these is a non-electrolyte?

  • A. NaCl solution
  • B. Distilled water ✅
  • C. HCl solution
  • D. KOH solution
Explanation: Distilled water does not produce ions and cannot conduct electricity.

6. In a galvanic cell, chemical energy is converted into:

  • A. Heat energy
  • B. Electrical energy ✅
  • C. Sound energy
  • D. Light energy only
Explanation: Galvanic cells use spontaneous chemical reactions to generate electrical energy.

7. The electrode where oxidation occurs is called:

  • A. Anode ✅
  • B. Cathode
  • C. Negative terminal
  • D. Electrolyte
Explanation: Oxidation always takes place at the anode.

8. Which metal is often used for electroplating jewelry?

  • A. Iron
  • B. Copper
  • C. Gold ✅
  • D. Zinc
Explanation: Gold electroplating is common for enhancing jewelry appearance and preventing corrosion.

9. In electrolysis, the positively charged electrode is called:

  • A. Anode ✅
  • B. Cathode
  • C. Electrode plate
  • D. Ion terminal
Explanation: The anode attracts negative ions and is positively charged in an electrolytic cell.

10. Which factor increases the rate of electroplating?

  • A. Using less current
  • B. Increasing current ✅
  • C. Using pure water
  • D. Removing electrolyte
Explanation: Higher current increases the rate at which metal ions deposit on the surface.

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