# How many moles are in sodium chloride in 150 mL of a 2 mM NaCl solution?

Mar 25, 2017

$\text{Concentration"="Moles of solute"/"Volume of solution}$. And here there are:
$150 \times {10}^{-} 3 \cancel{L} \times 2 \times {10}^{-} 3 \cdot m o l \cdot \cancel{{L}^{-} 1} = 3.00 \times {10}^{-} 4 \cdot m o l$ of solute.

#### Explanation:

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

And thus $\text{moles of solute"="volume"xx"concentration}$

And here, for this product we have:

$150 \times {10}^{-} 3 \cancel{L} \times 2 \times {10}^{-} 3 \cdot m o l \cdot \cancel{{L}^{-} 1} = 3.00 \times {10}^{-} 4 \cdot m o l$.

(I have changed the volume from $m L$ to $L$, and from $m m o l$ to $m o l$ simply by using the appropriate multiplier.