(a) Covalent compound do not form ions. Thus, no carrier of charge is present.
(b) Propanone
(c) Ethanoic acid reacts with sodium carbonate to produce carbon dioxide gas. To prove the presence of this gas allow it to pass through lime water (freshly prepared).
It turns lime water milky:
$$
\begin{aligned}
&2 \mathrm{CH}_{3} \mathrm{COOH}+\mathrm{Na}_{2} \mathrm{CO}_{3} \longrightarrow \\
&2 \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2}
\end{aligned}
$$
Test for the gas evolved
$$
\underset{\text { Lime water }}{\mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{CO}_{2}} \longrightarrow \underset{\text { Milky ppt. }}{\mathrm{CaCO}_{3}+\mathrm{H}_{2} \mathrm{O}}
$$
