Question

NaOH can also be prepared by electrolysis of aqueous NaCl. Amount of NaOH formed when 0.445 L of NaCl (aq) is electrolysed for 137 s with a current of 1.08 A, is :

• A. 0.09g
• B. 0.12g
• C. 0.06g
• D. amount of NaCl has not been given

Answer 1

The correct option is C 0.06g

According to Faraday's First Law of Electrolysis, chemical deposition due to flow of electric current through an electrolyte is directly proportional to the quantity of electricity (coulombs) passed through it i.e. mass of chemical deposition.

$\omega =Zit$

Where Z is a constant of proportionality and is known as electrochemical equivalent of the substance and $Z=E/F$, E is equivalent mass and F is faraday constant.
So $\omega =zit=\frac{40\times 1.08\times 137}{96500\times 1}=0.06g$