## Chemistry (7th Edition)

(a) $H_2CO_3$ (b) $HC{O_3}^-$ (c) $H_2O$ (d) $H_3PO_4$
The conjugate acid is the result of a base that receives one proton, therefore, you just need to add one hydrogen to the chemical formula, and sum 1 to the charge. For example: 1. Add the hydrogen: $H{CO_3}^- -- \gt H_2{CO_3}^-$ 2. Sum 1 to the charge: $H_2{CO_3}^- -- \gt H_2CO_3$