WAEC Chemistry 2017 Paper

Concept:Dilution factor is the ratio by which the original concentration is reduced after adding solvent.Explanation:Original concentration, $C_1 = 0.1\ \mathrm{mol\,dm^{-3}}$.Final concentration, $C_2 = 0.001\ \mathrm{mol\,dm^{-3}}$.The dilution factor is calculated as $\dfrac{C_1}{C_2}$.This tells how many times weaker the final solution is compared with the original.Substitute the values: $\dfrac{0.1}{0.001} = 100$.Thus, the solution was diluted 100-fold.Answer:$100.00$ (Option B).