Question

Which one is the correct equation that represents the first law of electrolysis?

• A. $mZ=ct$
• B. $m=cZt$
• C. $mc=Zt$
• D. $c=mZt$

Answer 1

Answer: (B)

$m=cZt$

If 'm' is the weight or amount of a substance deposited or liberated and 'c' ampere of current is passed for ’t’ seconds, then according to the law:

m $\alpha$ c x t

Or m = Z c t

Where Z is a constant, known as "electrochemical equivalent" of the substance. If one ampere of current is passed for one second; then w = Z. This means when one ampere of current is passed for one second; then the weight or amount of the substance deposited or liberated is exactly equal to its electrochemical equivalent.