A.(CH3)2AsO2H(Ka=6.40×10-7) B.ClCH2COOH(Ka=1.40×10-3) C.CH3COOH(Ka=1.76×10-5) D.HCOOH(Ka=1.77×10-4)
A.0.1% B.2% C.10% D.1%
A.NH4Cl B.NaNO3 C.NaAc D.NH4Ac E.NaCl