# What is the conjugate acid of HCO_3^-?

Feb 17, 2015

A conjugate acid is a substance that is formed when a base receives a proton, or ${H}^{+}$.

So, in order to determine the conjugate acid for a given base, all you have to know is that

$\text{base" + H^(+) -> "conjugate acid of that base}$

In your case, the base is hydrogen carbonate, or $H C {O}_{3}^{-}$. If you write the equation you'll get

$H C {O}_{3}^{-} + {H}^{+} \to {H}_{2} C {O}_{3}$

Carbonic acid, or ${H}_{2} C {O}_{3}$, will be the conjugate acid of hydrogen carbonate.