# How do we specify a concentration, given 0.02*mol of calcium chloride dissolved in a volume of water?

Jul 29, 2017

This question is ill-proposed...........

#### Explanation:

I could have a $1 \cdot L$ volume of $0.02 \cdot m o l \cdot {L}^{-} 1$ of $C a C {l}_{2}$ containing $0.02 \cdot m o l$ $C a C {l}_{2}$;

I could have a $10 \cdot L$ volume of $0.02 \cdot m o l \cdot {L}^{-} 1$ of $C a C {l}_{2}$ containing $0.2 \cdot m o l$ of $C a C {l}_{2}$;

I could have a $100 \cdot L$ volume of $0.02 \cdot m o l \cdot {L}^{-} 1$ of $C a C {l}_{2}$ containing $2.0 \cdot m o l$ of $C a C {l}_{2}$.

Can you work out the MASS of solute in each solution?

When we specify a concentration we refer to the quotient.......

$\text{Moles of solute"/"Volume of solution}$, and thus $\text{concentration}$ typically has the units $m o l \cdot {L}^{-} 1$.