Question

Assertion:- propene reacts with HBr to give isopropyl bromide. ....
Reason:- addition of Br2 to alkene takes place at the faster rate in the presence of ionizing substance

Answer 1

Answer:

it follows markonikovs rule

Answer 2

The complete question is whether both assertion and reason are true or not if not give reasons?

The answer is assertion is true whereas reason is false as explained below:-

The assertion is true as addition of HBr to propene follows Markonikov rule which states that during addition across unsymmetrical alkene the negative part of reagent goes to that carbon which has less number of hydrogen and positive to that with greater number of hydrogen.

Hence Br^- is added to second carbon is propene as it has less hydrogen and H^+ to 1st carbon as it has more carbon so product formed is 2 bromo propane or isopropyl bromide. Hence assertion is correct.

The reason is false as the rate of addition of Br2 to alkenes increases if addition take place in presence of organic solvent like carbon tetrachloride (CCl4) or the rate increases in presence of covalent compounds not ionic compounds.Hence reason is false.

So the correct answer is assertion is true while the reason is false.