During electrolysis, which electrode is called as cathode?

The negatively charged electrode connected to the negative terminal of the battery or voltmeter is known as cathode. The positively charged ions to the cathode and gets reduced to neutral atoms or molecules.

Give an example of a compound whose aqueous solution is a weak electrolyte.

Weak electrolyte ionise incompletely in the solution. Examples of weak electrolyte are solution of acetic acid, ammonia, carbonic acid, phosphoric acid, etc.

Write down the cathode reaction when an aqueous solution of MSO 4 ( M =metal) is electrolysed. Write with reason whether the reaction is oxidation or reduction.

The overall reaction is as follows: MSO 4 → M + 2 + SO 4 2 - In the above the reaction, the MSO 4 will be present as electrolyte and dissociates as M 2 + and SO 4 2 - along with H + and OH - ions in the aqueous solution. The half cell reactions are as follows: At Cathode: 2 M 2 + + 4 e - → 2 M As OH − has higher oxidation potential than SO 4 2 - , it gets preferentially oxidised. At Anode: 4 OH - → 2 H 2 O + O 2 + 4 e - Therefore, clearly in the cathode reaction clearly reduction occurs.

What is placed as a cathode to electroplate silver over a copper spoon?

Copper spoon is placed at the cathode to electroplate silver on it. A solution of silver nitrate is used as an electrolytic solution.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 10 - Electrolysis and Chemical Reaction>West Bengal Board-2019>Q 8

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10th West Bengal Board

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Liquid hydrogen chloride cannot conduct electricity, but molten sodium chloride can conduct electricity- Explain.

Important Questions on Electrolysis and Chemical Reaction

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10th West Bengal Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 10 - Electrolysis and Chemical Reaction>West Bengal Board-2019>Q 9

Write two differences between the conduction of electricity through a metallic wire and an electrolyte during electrolysis. In electrolyte refining of copper metal, impure copper rod is used as which electrode?