Substitution involves replacing an atom by another atom .
取代反应就是由一个原子取代另一分子中的一个原子。
Addition reaction n. 加成反应
Addition reactions involve two molecules joining together to form a single new molecule.
加成反应表示两个分子结合生成一个分子的过程。
Elimination n. 消去反应
Elimination involves the removal of a molecule from a large one. The addition of ethene to steam may be reversed by passing ethonal vapour over a hot catalyst such as pumic. A water molecule is eliminated.
CH3CH2OH(g) → CH2=CH2(g) + H2O(g)
消去反应表示的是从一个大分子中移走一个小分子的过程。例如在乙醇中加入催化剂可以从乙醇中移走水分子。
Hydrolysis n. 水解反应
Hydrolysis reactions involve breaking covalent bonds by reaction with water. The substitution of the bromine atom in bromoethane by hydrolysis is also a hydrolysis. The reaction proceeds much more slowly in water.