Ca(HCO3)2水溶液的电荷平衡式为( )
A. 2[Ca2+]= 2[CO32-]+[HCO3-]
B. [Ca2+]= 2[HCO3-]
C. 2[Ca2+]+[H+]=[HCO3-]+2[CO32-]+[OH-]
D. [H2CO3]+[H+]=[CO32-]+[OH-]
HPO42-的共轭碱是( )
A. H2PO4-
B. H3PO4
C. PO43-
D. OH-
下列溶液用酸碱滴定法能准确滴定的是()
A. 0.1 mol/L HF (pKa = 3.18)
B. 0.1 mol/L HCN (pKa = 9.21)
C. 0.1 mol/L NaAc [pKa(HAc) = 4.74]
D. 0.1 mol/L NH4Cl[pKb(NH3) = 4.75]
NaAc水溶液的质子平衡方程为( )
A. [Na+] = [Ac-]
B. [Na+] = [Ac-] + [OH-]
C. [HAc] + [H+] = [OH-]
D. [H+] = [Ac-] + [OH-]