# Question #8af7e

Dec 11, 2015

${m}_{N a C l} = 394.2 g$

#### Explanation:

The concentration is related to the mass through the number of mole:

${C}_{M} = \frac{n}{V}$

and the number of mole is related to the mass by:

$n = \frac{m}{M M}$

Therefore, we can first calculate the number of mole from the concentration and the volume by:

$n = {C}_{M} \times V = 4.50 \frac{m o l}{\cancel{L}} \times 1.50 \cancel{L} = 6.75 m o l$

Now from the number of mole we can find the mass by:

$m = n \times M M = 6.75 \cancel{m o l} \times 58.4 \frac{g}{\cancel{m o l}} = 394.2 g$

Thus we will need to weigh $394.2 g$ of $N a C l$ and add it to $1.50 L$ of water to prepare $4.50 M$ solution of sodium chloride.

Here is a video that will show you how to prepare a solution in the lab:
Lab Demonstration | Solution Preparation & Dilution.