Physics 2018 JAMB Past Questions - Question 13: The electrochemical equivalent of silver is 0.0012g/C. if 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5.0 minutes, the current must be

Correct Answer

D

Explanation

M = ZLt →I =M/Zt = 36/3X60X0.0012=100ATo calculate the current required for the deposition of 36.0g of silver, we can use the formula:

Charge (Q) = Current (I) × Time (t)

The charge required to deposit 36.0g of silver can be calculated using the electrochemical equivalent:

Charge (Q) = Electrochemical Equivalent (E) × Mass (m)

Substituting the given values:

Q = E × m
Q = 0.0012g/C × 36.0g
Q = 0.0432 C

Now, we can rearrange the formula for charge to solve for current:

I = Q / t

Substituting the values:

I = 0.0432 C / 5.0 minutes

Since the time needs to be in seconds for consistent units, we convert minutes to seconds:

I = 0.0432 C / (5.0 minutes × 60 seconds/minute)
I = 0.0432 C / 300 seconds
I ≈ 0.000144 A

Therefore, the current required to deposit 36.0g of silver by electrolysis in 5.0 minutes is approximately 0.000144 Amperes (A).