Ozonolysis of $but-1-ene$ followed by hydrolysis gives:

For the chemical reactions shown below,identify the correct statement from the following:

Assertion $(A)$: Reaction of $but-1-ene$ with $HBr$ gives $1-bromobutane$ as the major product.
Reason $(R)$: Addition of $HBr$ to unsymmetrical alkenes proceeds according to Markovnikov's rule.
The correct answer is

Propene,when heated with chlorine at approximately $500^\circ C$,forms:

Which of the following compounds has the minimum heat of hydrogenation?

The product of the addition reaction of ethene with $Br_2$ is......