The major product of this elimination reaction is an alkene, specifically, propene CH3CH=CH2 . The mechanism involved is E2 bimolecular elimination mechanism.Here's a step-by-step explanation of the E2 mechanism for this reaction:1. KOH is a strong base, and it will take a proton H+ from the carbon next to the carbon attached to the bromine atom Br . In this case, it will take a proton from the second carbon in the chain CH3CH2CH2Br .2. The electrons from the carbon-hydrogen bond will move to form a double bond between the first and second carbons in the chain.3. At the same time, the carbon-bromine bond breaks, and the bromine atom leaves as a bromide ion Br- .4. The final product is propene CH3CH=CH2 and the by-products are water H2O and potassium bromide KBr .The overall reaction can be written as:CH3CH2CH2Br + KOH CH3CH=CH2 + H2O + KBr