# I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is 250 mL, what will the molarity of the solution be?

Feb 8, 2016

The amount of substance, of $N a C l$ solute is constant. The answer is approx. $2$ $m o l \cdot {L}^{-} 1$.

#### Explanation:

$\text{Concentration}$ $=$ $\text{Mass"/"Volume of solution}$

Initially I had $0.345 \cdot \cancel{L} \times 1.5 \cdot m o l \cdot \cancel{{L}^{-} 1}$ $=$ $0.518$ $m o l$.

After I boil off some of the water, I have a new volume of solution but the SAME amount of SOLUTE, i.e. $0.518$ $m o l$.

Thus $\text{Concentration}$ $=$ $\frac{0.518 \cdot m o l}{0.250 \cdot L}$ $=$ ??mol*L^-1