Question

Which of the following is not correct ?

• A. $PhCH _{2} Br > PhCHBrCH _{3}> PhCBr \left( CH _{3}\right)_{2}\left( S _{ N } 1\right)$
• B. $R - I > R - Br > R - Cl \left( S _{ N } 2\right)$
• C. $CH _{2}= CH - Cl < CH _{2}= CH - CH _{2}- Cl < PhCH _{2}- Cl \left( S _{ N } 1\right)$
• D. $R - Cl < R - Br < R - I \left( S _{ N } 1\right)$

Answer 1

Answer: (A)

Reactivity towards $S_{N} 1$ reaction depends upon the stability of carbocation $3^{\circ} > 2^{\circ} > 1^{\circ}$. Thus, given order is wrong.