Identify the compound formed when But-2-ene is treated with $\text{KMnO}_4$ in dilute $\text{H}_2\text{SO}_4$.

Which one of the following compound will show addition of HBr to alkene according to markownikoff's rule?

When a mixture of two different alkyl halides reacts with metallic sodium in dry ether, the formation of a possible number of alkanes are-

Identify the product of reforming reaction of n-hexane in the presence of $\text{V}_2\text{O}_5$ over alumina.