Hydrogen donor

In chemistry a hydrogen donor is any chemical compound that has a hydrogen atom available for chemical interaction. Hydrogen donor is synonymous with a active hydrogen compound. A wide range of compounds fall within this category, from simple mineral acids to ordinary acids, carboxylic acids, amines, sulfonic acids to less obvious ones like carbon acids such as ethyl acetoacetate or Meldrum's acid. The pKa is a measure of the quality of a hydrogen donor.