Question

What current is to be passed for $0.25$ sec for deposition of certain weight of metal which is equal to its electrochemical equivalent?
$A.4A \\\ B.100A \\\ C.200A \\\ D.2A \\\$

Answer 1

In order to solve this question, we just simply apply faraday’s first law. After this we can get the applied current by the weight and electrochemical equivalent.
Electrochemical equivalent of the chemical element is the mass of that element that is transported by one coulomb of electric charge.

Formula used:
$W = ZIt....(1)$
Where W is the weight of the metal, Z is the electrochemical equivalent, I is the current and t is the time.

Complete step by step answer:
In order to solve this question, we can see that:
Here data given,
Time which is equal to$0.25$.
Also the electrochemical equivalent which is equal to $1gram{C^{ - 1}}$.
And the weight of the metal is equal to Z.
Now according to faraday’s first law of electrolysis,
We have;
$W = ZIt....(1)$
$\dfrac{W}{Z} = It$
Here, weight and electrochemical equivalent are equal , so they will be cancelled leaving one -one at the numerator and denominator. So when we put weight in place of electrochemical equivalent the ratio of weight and electrochemical equivalent will be one isto one.
After this, substituting the given values in equation$1$, we get;
\dfrac{1}{1} = I \times 0.25 \\\ I = 4amp \\\

So, the correct answer is Option A.

Note: According to the faradays first law, whenever a conductor is placed in a varying magnetic field, an electromotive force is induced. If the conductor circuit is closed, a current is induced which is called induced current.The chemical deposition due to flowing of a current in an electrolytic medium is directly proportional to the quantity of electricity passing through it. Electrochemical equivalent of the chemical element is the mass of that element that is transported by one coulomb of electric charge.