Question

Which of the following is/are the criteria for an electrolyte used in salt bridge?

• A. Should get oxidised/reduced at electrode
• B. Should not get oxidised/reduced at electrodes
  
• C. Cations and anions should have same mobility
• D. Electrolyte should not react with the ions in the solution
  

Answer 1

Answer: (B), (C), (D)

Electrolyte should not react with the ions in the solution


Salt bridge is a U–shaped inverted tube that contains a gel (paste of agar-agar powder) permeated with an inert electrolyte.
These salt bridge electrolytic ions will polarise some of the oppositely charged ions in the solution towards themselves and keeps the cell working.
The criteria for an electrolyte to be used in salt bridge are
1. The electrolytes should consist of cations and anions having same mobility.
2. The electrolytic ions should not react with the ions in the solution.
3. The electrolyte should not get oxidised/reduced at electrodes.
Thus, (b), (c) and (d) are the criteria for an electrolyte used in salt bridge.