Question 15.1: Write the formula for (a) the conjugate base of H2O and of H...

(a) To write the conjugate base of an acid, remove one proton from the acid formula:

H_2O \xrightarrow[]{-H^+} OH^-               (conjugate base)

HNO_3 \xrightarrow[]{-H^+} NO_3^-                  (conjugate base)

Remember: The difference between an acid or a base and its conjugate is one proton, H^+.

Note that, by removing an H^+ , the conjugate base becomes more negative than the acid by one minus charge.

(b) To write the conjugate acid of a base, add one proton to the formula of the base:

SO_4^{2-} \xrightarrow[]{-H^+} HSO_4^-               (conjugate acid)

C_2H_3O_2^- \xrightarrow[]{-H^+} HC_2H_3O_2                          (conjugate acid)

In each case the conjugate acid becomes more positive than the base by a +1 charge due to the addition of H^+ .