Question

Calculate the amount of the water 'in ml' which must be added to a given solution of concentration of 40 mg silver nitrate per ml, to yield a solution of concentration of 16 mg silver nitrate per ml?

Answer 1

$\frac{40mg}{1ml}\times 1=\frac{16mg}{1ml}\times V_2$

$\therefore$ $V_2=\frac{40}{16}=2.5$ ml of water is to be added.