# How do you solve dilution problems in chemistry? For example: if 211 mL of water is added to 5.00 mL of 3.24 M NaCl solution, what is the concentration of the dilute solution? ____ M.

$\text{Concentration} \equiv 0.0750 \cdot m o l \cdot {L}^{-} 1. \ldots \ldots .$
The defining formula is $\text{Concentration"="Moles of solute"/"Volume of solution}$; or $C = \frac{n}{V}$, and thus for your problem we work out....
${C}_{2} = \frac{{C}_{1} \times {V}_{1}}{{V}_{1} + {V}_{2}} = \frac{5.00 \times {10}^{-} 3 \cdot L \times 3.24 \cdot m o l \cdot {L}^{-} 1}{\left(211 + 5\right) \times {10}^{-} 3 L} = 0.0750 \cdot m o l \cdot {L}^{-} 1$
The numerator addresses the number of moles of solute, and the volume are added in the denominator. Note that the answer is consistent dimensionally............$1 \cdot m L = {10}^{-} 3 \cdot L$