# What is the molarity of a solution with 20 moles of salt (NaCl) in 10 liters of solution?

Mar 26, 2016

$\text{Molarity"="Amount of solute (moles)"/"Volume of solution (litres)}$ $=$ $\frac{20 \cdot m o l}{10 \cdot L}$ $=$ $2 \cdot m o l \cdot {L}^{-} 1$
Molarity is a measure of concentration, $\text{amount of substance (mol)"/"volume of solution (L)}$. The units of molarity are naturally $\text{moles per litre of solution}$ $=$ $m o l \cdot {L}^{-} 1$.
To get the amount of substance dissolved in a given volume, all I have to do is multiply the concentration by volume, i.e. $m o l \cdot {L}^{-} 1 \times L$ $=$ $m o l$.
If I take $1 L$ of your solution, how many moles of $N a C l$ does it contain?