Question

The quantity of electricity required to liberate 32 g of oxygen is:

• A. 1 faraday
• B. 2 faradays
• C. 3 faradays
• D. 4 faradays

Hint:

1 mole of oxygen requires 2 faradays of electricity, as 4 moles of electrons are needed to reduce 1 mole of oxygen.

Answer 1

The Correct Option is B

Step 1: Apply the concept of Faraday's law.
The quantity of electricity required to liberate a specific mass of a substance during electrolysis is related to Faraday's law. The formula is: \[ Q = n \times F \quad \text{where} \quad Q = \text{Quantity of electricity}, \quad n = \text{moles of substance}, \quad F = \text{Faraday constant (96500 C)} \]
Step 2: Calculate the moles of oxygen.
The molar mass of oxygen is 32 g, so 32 g of oxygen is equal to 1 mole of oxygen.
Step 3: Calculate the quantity of electricity.
To liberate 1 mole of oxygen, 4 moles of electrons are required (from the reaction \(2\text{O}_2 + 4e^- \rightarrow 2\text{O}_2\)). Therefore, the required quantity of electricity is 2 faradays.
Final Answer: \[ \boxed{2 \, \text{faradays}} \]