# What is the molarity of the solution made by adding 5 mL of 0.1 M HCl to 45 mL of the water is 0.01?

Sep 20, 2017

Well, the new concentration is $0.01 \cdot m o l \cdot {L}^{-} 1$, i.e. you have diluted the original concentration tenfold....

#### Explanation:

And we use the relationship...

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

$= \frac{5 \times {10}^{-} 3 \cdot L \times 0.1 \cdot m o l \cdot {L}^{-} 1}{50 \times {10}^{-} 3 \cdot L} = 0.01 \cdot m o l \cdot {L}^{-} 1$....

How did I know that the volume was $50 \cdot m L$..