State whether the following statement is true or false:
Heating ethanol at $443 \,K$ with excess concentrated sulphuric acid results in the dehydration of ethanol to give ethene.

What happens when (Give equations also):
$(i)$ Methane reacts with excess of chlorine in the presence of diffused sunlight.
$(ii)$ Ethanol undergoes combustion.
$(iii)$ Ethyl alcohol reacts with acidified potassium dichromate.

Which is the simplest compound of the ketone group?

$A$ compound $C$ (molecular formula $C_2H_4O_2$) reacts with $Na$ metal to form a compound $R$ and evolves a gas which burns with a pop sound. Compound $C$ on treatment with an alcohol $A$ in the presence of an acid forms a sweet-smelling compound $S$ (molecular formula $C_3H_6O_2$). On addition of $NaOH$ to $C$,it also gives $R$ and water. $S$ on treatment with $NaOH$ solution gives back $R$ and $A$. Identify $C$,$R$,$A$,$S$ and write down the reactions involved.

$(a)$ Write chemical equations for the reactions of ethanoic acid with:
$(i)$ Sodium
$(ii)$ Sodium carbonate
$(iii)$ Ethanol in the presence of conc. $H_{2}SO_{4}$.
$(b)$ State the role of concentrated sulphuric acid in the esterification reaction.
$(c)$ Write one use of ethanoic acid.

What is the difference between two consecutive members in a homologous series of alkanes in terms of:
$(i)$ molecular mass.
$(ii)$ number of atoms of elements.