三、胺的化学性质 1.碱性 NH3+HCl—>NH4C H OI CHaNH,+H- CH3NH CH3NH2+ H2O RNH2+H2O÷=RNH3+OH IRNH3JIOH'I Kb rnH, pKb=-logkb Kb越大,pKb越小,则减性越强 k Ka X Kb=Kw=10-4 pKa+pKb=14三、胺的化学性质 1. 碱性 k NH3 + HCl NH4 Cl CH3 NH2 + H CH3 NH3 OH - CH3 NH2 + H2 O + RNH2 + H2 O Kb RNH3 + OH - Kb = RNH3 OH - RNH2 pKb = -logKb Kb越大，pKb越小，则碱性越强 Ka × Kb = Kw =10 –14 pKa + pKb = 14