Normality (Standard) is a measure of concentration used in chemistry, specifically for solutions. It is defined as the number of equivalents of solute per liter of solution. This concept is particularly useful when dealing with reactions that involve acids and bases, where the reactivity depends on the number of reactive units, or equivalents, rather than just the total amount of solute. In practical terms, a 1 N (one normal) solution contains one equivalent of solute in one liter of solution. For example, in the case of sulfuric acid, which can donate two protons, a 1 N solution would contain 0.5 moles of H2SO4 per liter. Normality helps chemists understand and calculate the amounts needed for reactions accurately.