Answer
a. $H_3PO_4/H_2P{O_4}^-$ and $H_3O^+/H_2O$
b. $H_2O/OH^-$ and $HCO{_3}^-/CO{_3}^{2-}$
c. $H_3PO_4/H_2P{O_4}^-$ and $NH{_4}^+/NH_3$
d. $HNO_2/NO{_2}^-$ and $CH_3CH_2NH{_3}^+/CH_3CH_2NH_2$
Work Step by Step
1. Identify the reactant that acts as an acid, and what it turns after donating a proton.
a. $H_3PO_4 \longrightarrow H_2P{O_4}^-$
b. $H_2O \longrightarrow OH^-$
c. $H_3PO_4 \longrightarrow H_2P{O_4}^-$
d. $HNO_2 \longrightarrow N{O_2}^-$
- These are the first acid-base pairs.
2. Identify the reactant that act as a base, and its conjugate acid.
a. $H_2O \longrightarrow H_3O^+$
b. $C{O_3}^{2-} \longrightarrow HC{O_3}^-$
c. $NH_3 \longrightarrow N{H_4}^+$
d. $CH_3CH_2NH_2 \longrightarrow CH_3CH_2N{H_3}^{+}$
