Question 113 of 198 in Electrolysis

The electrolysis of sodium chloride solution

1 mark · Easy

During the electrolysis of sodium chloride solution, what ion builds up near the cathode making the solution there alkaline?

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

Hydroxide ion (OH⁻)

Also accept: hydroxide; OH- ions; OH⁻; hydroxide ions

Common mistakes: Hydrogen ions; Sodium ions

Show mark scheme and worked solution

Marking points

B1 · 1 mark · States hydroxide ion (OH⁻) or equivalent as making cathode solution alkaline.

Worked solution

The ion that builds up near the cathode is the hydroxide ion, OH⁻.

Report a problem with this question