An electrolysis cell consumed a charge of 4.00 C in 5.00 minutes - VCE - SSCE Chemistry - Question 9 - 2021 - Paper 1

To find the number of moles of electrons consumed, we can use the relation between charge, moles of electrons, and Faraday's constant:

1. Faraday's Constant (F): Approximately 96485 C/mol, which indicates the amount of charge required to transfer one mole of electrons.

2. Formula to Calculate Moles (n):

   $n = \frac{Q}{F}$ where:

   • $Q$ is the total charge (in coulombs)
   • $n$ is the number of moles of electrons.

3. Substituting the Known Values:

   • Given charge $Q = 4.00 \, \text{C}$,
   • We can calculate:

   $n = \frac{4.00}{96485} \approx 4.15 \times 10^{-5} \text{ mol}$

4. Conversion to the correct significant figures: The charge is in 4.00, which has three significant figures. Thus, we ensure the final answer also reflects this:

   $n \approx 4.15 \times 10^{-5} \text{ mol}$

Thus, the number of moles of electrons consumed is approximately 4.15 × 10⁻⁵ mol.