Normality definition

Normality is similar to molarity, but uses equivalents, not moles of the substance. It is expressed as number of equivalents per liter. Thus the same solution can have different normalities for different types of reaction - for example 1M sulfuric acid solution is 2N for acid/base reactions, but it is 1N in the reaction of barium sulfate precipitation. To calculate normality of the solution you have to know its exact molarity as well as stoichiometry of the reaction substance will be used in.

To convert between normality and other types of concentration find molarity of the solution first.

Normality is expressed in [equivalent/L] units.

Despite the fact that normality depends on the reaction, some reagents are sold in normal concentrations. It may happen when the reagent is used solely for one specific reaction, or when the reagent always - for all practical purposes - behave as if it had the same normality. Good example of such reagent is hydrochloric acid, which is 1N regardless of whether it is used for neutralization or chlorides precipitation.