Notice that when representing concentration units they are dependent upon moles and the same set of stoichiometry guidelines govern reactions in solution. There is one extra bit of complexity that comes into play as we need to keep track of the volume of the solutions we are analyzing.
4.6 Solution Stoichiometry and Chemical Analysis
A common laboratory technique to determine the concentration of a solution is called a titration. In a titration a standard solution, with a known concentration, is titrated against a solution of unknown concentration and the concentration of the unknown solution can be calculated.