A.PO43-(H3PO4的pKa1=2.12;pKa2=7.20;pKa3=12.36) B.C2O42-(H2C2O4的pKa1=1.22;pKa2=4.19) C.Ac-(HAc的pKa=4.74) D.HCOO-(HCOOH的pKa=3.74)
A.6.3~2.3B.8.3~2.3C.8.3~4.3D.6.3~4.3
A.NH3的Kb太小 B.(NH4)2SO4不是酸 C.(NH4)2SO4中不含游離H2SO4 D.NH4+的Ka太小