Question

In the electrolysis of acidulated water, it is desired to obtain \(1.12\ \text{cc}\) of hydrogen per second under STP condition. The current to be passed is:

• A. \(1.93\ \text{A}\)
• B. \(9.65\ \text{A}\)
• C. \(19.3\ \text{A}\)
• D. \(0.965\ \text{A}\)

Hint:

At STP, always use (22400 textcc mol^-1) for gases and remember that (1 textFaraday = 96500 textC) when applying Faraday’s laws of electrolysis.

Answer 1

The Correct Option is B

Step 1: Volume of hydrogen produced per second \[ V = 1.12\ \text{cc s}^{-1} \] At STP, \(1\) mole of gas occupies \(22400\ \text{cc}\). Step 2: Calculate moles of hydrogen produced per second \[ \text{Moles of } \text{H}_2 = \frac{1.12}{22400} = 5 \times 10^{-5}\ \text{mol s}^{-1} \] Step 3: Electrochemical relation for hydrogen evolution For the reaction: \[ 2\text{H}^+ + 2e^- \rightarrow \text{H}_2 \] \(2\) moles of electrons (i.e., \(2F\) charge) are required to produce \(1\) mole of hydrogen gas. Step 4: Calculate current required Charge required per second: \[ I = (5 \times 10^{-5}) \times 2F \] \[ I = 5 \times 10^{-5} \times 193000 \] \[ I = 9.65\ \text{A} \] Hence, the required current is \(\boxed{9.65\ \text{A}}\).