which base listed below would be strongest given the corresponding acid ionization constants for their conjugate acids?
Ch3COO^-1; Ka(CH3COOH)=1.8x10^-5
PO4 ^-3; Ka(HPO4^-1)= 4.2x10^-13
NO2 ^-1; Ka(HNO2)= 7.1x10^-4
HCO3^-1; Ka(H2CO3)=4.5x10^-7
F^- ; Ka(HF)= 6.8x10^-4