H3PO4的pKa1,pKa2,pKa3分別是2.12,7.20,12.40,欲用H3PO4和NaOH配制pH=7.20的緩沖溶液時,應(yīng)使用H3PO4和NaOH的物質(zhì)的量之比為:()
A.1:2B.2:3C.3:2D.1:1
H3PO4的pKa1,pKa2,pKa3分別是2.12,7.20,12.40,欲用H3PO4和NaOH配制pH=2.12的緩沖溶液時,應(yīng)使用H3PO4和NaOH的物質(zhì)的量之比為:()
A.1:1B.1:2C.2:1D.2:3
A.Na2OH(Kb=1.0x10-9) B.NH3·H2O(Kb=1.8x10-5) C.HAc(Ka=1.8x10-5) D.HNO2(Ka=5.0x10-4)