`S_(N)1` reaction underoges through carbocation intermediate as follows:
`R-X(aq.) overset("Slow") hArr R^(+)(aq.)+`
`X^(-) (aq.) underset ("fast") overset(H_(2)O)to ROH(aq.)+H^(+)(aq.)`
[R=t-Bu, iso-Pr, Me] `(X=Cl, Br, I)`
The correct statements are
I. The decreasing order of rate of `S_(N)1` reaction is `t-BuXgtiso-PrXgtEtXgtMeX`
II. The decreasing order of ionisation energy is `MeXgtEtXgtiso-PrXgt t-BuX`
III. The decreasing order of energy of activation is `t-BuX gt iso- PrXgtEtXgtMeX`

Options

A. I & II are correct
B. I & III are correct
C. II and III are correct
D. I, II & III are correct

Answer

A

Explanation

Rate of `S_(N)1` reaction is a
`tBu X gt iso -Pr Xgt Et gt MeX`
So order of activation energy
`t-BuX lt iso -PrXC lt EtXlt MeX`
order of ionisation energy
`t Bu X lt iso-BrX-EtX lt MeX`