Concentration Of Solutions

Let us calculate how much volume of a concentrated 1.0 M NaOH solution is needed to prepare 1000 mL of a 0.2 M NaOH solution. We can determine this by using the general dilution formula, $M_1 \times V_1 = M_2 \times V_2$. In this scenario, the desired molarity $M_1$ is 0.2 M and the desired final volume $V_1$ is 1000 mL. The initial molarity $M_2$ of our stock solution is 1.0 M, and we need to find the initial volume, $V_2$. Substituting these values into our equation gives $0.2 \text{ M} \times 1000 \text{ mL} = 1.0 \text{ M} \times V_2$. Solving for the unknown volume, we get $V_2 = \frac{0.2 \times 1000}{1.0}$. This mathematical operation evaluates to a required volume of mL. Therefore, to prepare the mixture, we take this exact amount of concentrated solution and add enough water to dilute it to make it litre.