Concept:Markovnikov's rule applies to unsymmetrical alkenes.
Explanation:When
HBr adds to an unsymmetrical alkene, the hydrogen atom attaches to the carbon atom that already has more hydrogen atoms.
The bromine atom attaches to the carbon atom that has fewer hydrogen atoms.
Now check each option.
But-2-ene is
CH3​−CH=CH−CH3​.
This is a symmetrical alkene, so Markovnikov's rule does not give a unique product.
Hex-3-ene is
CH3​CH2​−CH=CH−CH2​CH3​.
This is also symmetrical.
Ethene is
CH2​=CH2​.
This is symmetrical too.
2-methylpropene is
CH2​=C(CH3​)2​.
This is an unsymmetrical alkene.
So it shows addition of
HBr according to Markovnikov's rule.
The reaction is:
CH2​=C(CH3​)2​+HBr→(CH3​)3​CBrThe product formed is 2-bromo-2-methylpropane.
Answer:Option D: 2-methylpropene