A.[H2CO3]=[HCO3-] B.[HCO3-]=[CO32-] C.[H2CO3]=[CO32-] D.[H2CO3]=[H+]
用NaOH溶液滴定H3PO4溶液至pH=4.7時(shí),溶液的簡(jiǎn)化質(zhì)子條件為() (H3PO4的pKa1~pKa3分別是2.12、7.20、12.36)
A.[H3PO4]=[H2PO4-] B.[H2PO4-]=[HPO42-] C.[H3PO4]=[HPO42-] D.[H3PO4]=2[PO43-]
今有[a]NaH2PO4,[b]KH2PO4和[c]NH4H2PO4三種溶液,其濃度c(NaH2PO4)=c(KH2PO4)=c(NH4H2PO4)=0.10mol/L,則三種溶液的pH的關(guān)系是() [已知H3PO4的pKa1~pKa3分別是2.12、7.20、12.36;pKa(NH4+)=9.26]
A.a=b=c B.a<b<c C.a=b>c D.a=b<c