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.