What mass of salt is needed to make 300 mL of a 2g/L solution?

The mass of salt needed for the solution can be found by using the concept of concentration, which is given as mass of solute (in this case salt) per volume of solution. Concentration in this form is generally expressed as . In general, can also be interpreted as . The given volume of solution is 300 mL which is less than 1000mL and the given concentration is 2 g/L. Because the concentration is based on the volume of 1000 mL, but our volume of solution is different, we first find the mass of the solute for one litre (using the given concentration) and then we apply a ratio (proportional calculation) based on the ratio of the solution volume to one litre (300mL is 0.3 of a litre) to find out how much salt we need in our 300mL solution.