A semi-normal solution is a solution that contains 0.5 gram equivalents of solute per litre of solution. It has a normality of 0.5 N, meaning it is half as strong as a 1 normal (1 N) solution. For example, if the equivalent weight of a substance is 40 g, then dissolving 20 g of that substance in water and making the final volume 1 litre gives a semi-normal solution.
