Answer
(a) $N{H_4}Cl$
Work Step by Step
(a) $N{H_4}^+$ is the conjugate acid of a weak base: Weak acid.
$Cl^-$ is the anion of a strong acid: pH-neutral.
Acidic solution.
(b) $Na^+$: Cation of a strong base: pH-neutral
$Cl^-$ is the anion of a strong acid: pH-neutral.
Neutral solution.
(c) $K^+$: Cation of a strong base: pH-neutral
$N{O_2}^-$ is the conjugate base of a weak acid: Weak base.
Basic solution.
(d)$Ca^{2+}$: Cation of a strong base: pH-neutral
$N{O_3}^-$ is the anion of a strong acid: pH-neutral.
Neutral solution.
