Write the formula of the conjugate acid of base HCO3-,HPO2-,PO43-,SO32-

1 answer

Bases have fewer H atoms; acids have more H atoms.
HCO3^- add a H atom to make H2CO3.
HPO^2- + H^+ ==> H2PO2-
PO4^3- + H^+ ==> HPO4^2-
Get the idea?