What is the number of moles of $sp^2$ hybridized carbon atoms present in $n$ moles of isopentane?

$A$ mixture of ethyl iodide and $n$-propyl iodide is subjected to Wurtz reaction. The hydrocarbon which will not be formed is

The correct order of reactivity of $(I)$,$(II)$,and $(III)$ towards addition reactions is:
$(I)$ Cyclopropane
$(II)$ Cyclobutane
$(III)$ Cyclopentane

The reaction of an alkyl bromide $(X)$ with $Na$ in dry ether gives $4, 5-$diethyl octane. Then $(X)$ is:

Which of the following reactions produce an alkane as the product?

What does petroleum mainly consist of?