# If you need to make a 5.6% solution of NaCl using 9.6g of NaCl, how many grams of water is needed?

Apr 27, 2016

$161.8 \cdot g$ of water is required.

#### Explanation:

"Mass of sodium chloride"/"Mass of solution"xx100% = 5.6%

So $\frac{9.6 \cdot g}{\text{Mass of solution}} = 0.056$

So $\frac{9.6 \cdot g}{0.056} = \text{Mass of solution} = 171.4 \cdot g$

Of course the mass of solution includes the $9.6 \cdot g$ mass of sodium chloride. So we require $171.4 \cdot g - 9 , 6 \cdot g \text{ of water}$ $=$ $161.8 \cdot g$