Answer
(a) The solution formed is basic.
(b) Acidic.
(c) Neutral.
(d) Acidic.
Work Step by Step
(a) $Na^+$ is pH-neutral and $HC{O_3}^-$ acts as a weak base in pure water: The solution formed is basic.
(b) $CH_3CH_3N{H_3}^+$ is a weak acid, and $Cl^-$ is pH-neutral:
The solution formed is acidic.
(c) $K^+$ is pH-neutral and so is $N{O_3}^-$: The solution formed is neutral.
(d) $Fe^{3+}$ is a weak acid and $N{O_3}^-$ is pH-neutral: The solution formed is acidic.
