Question

In a silver voltameter 2.16 g of silver is deposited in 10 minutes. The heat production in 20 $\Omega$ resistor in the same period is nearly:

• A. 198.2 kJ
• B. 124.4 kJ
• C. 171.2 kJ
• D. 141.2kJ

Answer 1

The correct option is B 124.4 kJ

The expression for the mass of silver deposited is $m=zIt$

This can be rearranged to calculate the current.

$I=\frac{m}{Zt}=\frac{2.16\times 96500}{108\times 10\times 60}=3.22A$

The expression for the heat produced is $H=I^{2}Rt=3.22\times 20\times 10\times 60=124.4kJ$.