Define oxidising agents. Explain its role in the oxidation of alcohols to acids. Write the oxidation reaction of ethanol.

$A$ 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.

State the valency of each carbon atom in $(i)$ an alkane and $(ii)$ an alkyne.

Carbon has four electrons in its valence shell. How does carbon attain stable electronic configuration?

$(a)$ Why is hard water not suitable for washing clothes with soap?
$(b)$ Why does micelle formation take place when soap is added to water?
$(c)$ What is saponification?

What are soaps? Why do they form scum with hard water?