Which of the products will be major product in the reaction given below? Explain
`CH_(3)CH=CH_(2)+Hitounderset((A))(CH_(3)CH_(2)I)+underset((B))(CH_(3)CHICH_(3))`

Explanation

The given reaction is an example of electrophilic addition reaction in which a proton adds first to form a carbocation which is then attacked by `I^(-)`

Since `2^(@)` carbocation is more stable than `1^(@)` carbocation, therefore, 2-iodopropane (B) is the major product and 1-iodopropane (A) is the minor product.
The same conclusion can be drawn from Markovnikov's rule which states that the major product is obtained by addition of the negative part of the adding molecule to that carbon atom of the double bond which carries lesser number of hydrogen atom. thus, 2-iodopropane (B) is the major product while 1-iodopropane (A) is the minor product.