Which two of the following compounds belong to the same homologous series?
$C_{2}H_{6}O, C_{2}H_{6}O_{2}, C_{2}H_{6}, CH_{4}O$

An organic compound $'A'$ has a molecular formula $C_{2}H_{6}O$. $'A'$ on oxidation gives compound $'B'$,which produces effervescence with baking soda.
$(i)$ Identify $'A'$ and $'B'$.
$(ii)$ Write the chemical reaction of $'B'$ with baking soda.

The formula of citric acid is shown below:
$\begin{matrix}
\,\,\,\,\,COOH \\
|\,\,\,\,\,\,\, \\
CH_{2}\, \\
|\,\,\,\,\, \\
HO-C-COOH \\
|\,\,\,\,\, \\
\,CH_{2} \\
|\,\,\,\,\, \\
\,\,\,\,\,\,COOH \\
\end{matrix}$
State the name of the $-COOH$ functional group present in citric acid.

An aldehyde as well as a ketone can be represented by the same molecular formula,say $C_{3}H_{6}O$. Write their structures and name them. State the relation between the two in the language of science.

Name the reaction which is commonly used in the conversion of vegetable oils to fats. Explain the reaction involved in detail.

What will you observe on adding a $5\%$ alkaline potassium permanganate solution drop by drop to some warm ethanol taken in a test tube? Write the name of the compound formed during the above chemical reaction.