Question

A current of 3.46 A is passed through a Sn(NO3)2 solution for 1.40 h . How much tin is plated out of the solution?

Answer 1

About 10.7 grams.

Step-by-step explanation:

The reduction reaction is represented by:

`\displaystyle \text{Sn}^(2+)_\text{(aq)} + 2e^- \longrightarrow \text{Sn}_\text{(s)}`

A current of 3.46 amperes (C/s) is passed through the solution for 1.40 hours. The total amount of charge is hence:

`\displaystyle 1.40\text{ hour} \cdot \frac{3600\text{ s}}{1\text{ hour}}\cdot \frac{3.46\text{ C}}{1\text{ s}} = 1.74* 10^4\text{ C}`

One mole of solid Sn is transferred per two moles of electrons. Hence, using Faraday's constant:

`\displaystyle 1.74* 10^4\text{ C} \cdot \frac{1\text{ mol e$^-$}}{96485\text{ C}} \cdot \frac{1\text{ Sn}}{2\text{ mol e$^-$}}\cdot \frac{118.71\text{ g Sn}}{1\text{ mol Sn}} = 10.7\text{ g Sn}`

In conclusion, about 10.7 grams of tin is plated out of the solution.