Answer
(a) $N{H_4}^+$: Ammonium
(b) $H_2CO_3$: Carbonic acid.
(c) $HBr$: Bromidric acid.
Work Step by Step
- To get the conjugate acid, just add a hydrogen to the base's formula and add 1 to the charge:
(a) $NH_3 - NH_4 - N{H_4}^+$
(b) $HC{O_3}^- - H_2{CO_3}^- - H_2CO_3$
(c) $Br^- - HBr^- - HBr$
Name:
(a) Ammonium is a general name for protonated amine groups, so we use it to describe the $NH_4^+$ cation too.
(b) $H_2CO_3$ is formed from the carbonate group, so it is the carbonic acid.
(c) $HBr$ is formed from a bromide ion, so it is the bromidric acid.