Question

Assertion: propene reacts with HBr to give isopropyl bromide
Reason: addition of Br2 to alkene takes place faster rate on the presence of ionizing substance.
OPTIONS..
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct of explanation of A
C) A is correct but R is incorrect
D) A is incorrect but R is correct

Answer 1

The correct answer is (C), A is correct but reason is false as:--

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 nor ionic compounds.Hence reason is false.

So correct answer is (C), A is correct but R is false.

Answer 2

I hope is a answer correct.