Which of the following will not give one monochloro product?

Identify the correct statements from the following:
$(i)$ Petrol and $CNG$ operated automobiles cause less pollution.
$(ii)$ Alkanes having tertiary hydrogen can be oxidised to alcohols by $KMnO_4$.
$(iii)$ Methane can be prepared by Kolbe's electrolytic method.
$(iv)$ Alkyl chloride on reduction with zinc and dilute hydrochloric acid gives alkane.

An unknown compound $X$ on chlorination followed by Wurtz reaction and dehydrohalogenation gives ethene. Provide the complete reaction sequence in a stepwise manner.

Which hydrocarbon is produced when sodium propionate is heated with sodalime?

The angle strain in cyclopropane is:

Give the general formula of an alkyl group.