Definition of Condensation Reaction A condensation reaction is a chemical reaction in which two molecules or moieties(functional groups) combine to form one single molecule, together with the loss of a small molecule When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride, methanol, or acetic acid 两个及两个以上有机化合物分子通过反应,失 去一个小分子,形成一个新的较大分子;或同一分 子发生分子内反应,失去一个小分子,形成新分子 的反应,也称为缩合反应。Definition of Condensation Reaction 两个及两个以上有机化合物分子通过反应，失 去一个小分子，形成一个新的较大分子；或同一分 子发生分子内反应，失去一个小分子，形成新分子 的反应，也称为缩合反应。 A condensation reaction is a chemical reaction in which two molecules or moieties (functional groups) combine to form one single molecule, together with the loss of a small molecule. When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride, methanol, or acetic acid