Molar Solutions

Molar Solutions

A 1 molar solution is a solution in which 1 mole of a compound is dissolved in a total volume of 1 litre.

For example:
The molecular weight of sodium chloride (NaCl) is 58.44, so one gram molecular weight (= 1 mole) is 58.44g. If you dissolve 58.44g of NaCl in a final volume of 1 litre, you have made a 1M NaCl solution.

To make a 0.1M NaCl solution, you could weigh 5.844g of NaCl and dissolve it in 1 litre of water; OR 0.5844g of NaCl in 100mL of water (see animation below); OR make a 1:10 dilution of a 1M sample.

Making a 0.1M NaCl solution (w/v)

Many of the solutions you will use are described in terms of their molarity, so check that you are comforable with the concept by describing how you would make 500mL of a 0.05M NaCl solution.