Question

How do you determine conjugate acid and base pairs?

Answer 1

See this old answer.

Explanation:

The conjugate base of any acid `HA` simply the acid MINUS a proton, `H^+`; when we do this for `HA` we get `A^-`. Likewise the conjugate acid of any base `A^-` is simply the base plus a proton, `H^+`, to give `HA`. Mass and charge are conserved.

To use sulfuric acid as an example, we start with the `H_2SO_4` formula; less a proton, this gives `HSO_4^-` as the conjugate base, and the conjugate base of `"bisulfate"` is `"sulfate"` ion, `SO_4^(2-)`. All I am doing is exchanging protons, `H^+`, and conserving mass and charge.

Can you tell the conjugate bases of the following acids: `HClO_4`; `H_3PO_4`; `NH_4^+`; `NH_3`; `NH_2^-`; `HC-=CH`; `NH^(2-)`?