Concept preview

What you will be able to do

1. 01Define and calculate molar concentration
2. 02Find the mass of solute or volume of solution from molarity
3. 03Apply the dilution equation $c_1V_1 = c_2V_2$

The concentration of a solution is the amount of solute in a given volume of solution. A concentrated solution has a lot of solute; a dilute one has little. Chemists measure concentration as molar concentration or molarity: the number of moles of solute per litre of solution, $c = \dfrac{n}{V}$, with units of $\mathrm{mol/L}$, written $\mathrm{M}$ and spoken 'molar'. Note it is per litre of SOLUTION, not of solvent.