$\text{ 1-Butene }\stackrel{\mathrm{HCl}}{\to }\text{ A}$

$\text{ 1-Butene }\underset{\mathrm{Peroxide}}{\overset{\mathrm{HCl}}{\to }}B;\mathrm{A}\text{ and }\mathrm{B}\text{ are }$

1-Butene when reacts with HCl, it follows Markownikoff's rule to form isobutyl chloride as a product. Both reactions give the same product as HCl does not show the peroxide effect.