Question

In electrolysis, if the duration of the passage of current is doubled, then the mass liberated is

• A. Doubled
• B. Increased
• C. Halfed
• D. Remains the same

Answer 1

The correct option is A Doubled

According to Faraday's First Law of electrolysis, mass of the substance (W) deposited or liberated at any electrode is directly proportional to the quantity of electricity or charge (Q) passed.

$W=Z\times I\times t;\because (Q=I\times t)$
Where,
$W$ is the mass of the substance produced in g.

$Z$ is the electrochemical equivalent, which is the mass of substance produced at the electrode during electrolysis by one coulomb of charge.

$I$ is the current in Ampere (A)
$t$ is the time in seconds

Hence, if the duration of the passage of current (t) is doubled then,
$W=Z\times I\times \left(2t\right)=2(Z\times I\times t)=2W$

So, the mass liberated (W) will also be doubled.