Question

A (Ni+2) solution is electrolyzed using a current of 1.25A. What mass of (Ni0 ) plates out in 30 minutes.

Answer 1

The decay formula can be written as:

$N=N_0\times 2^{-\frac{t}{t_{1/2}}}$

Therefore:

$t=-log_2(\frac{N}{N_0})\times t_{1/2}=-log_2(\frac{0.5g}{100g})\times 20\,minutes\approx153\,minutes$

Answer: 153 minutes