\((2)\) Methoxy group is electron releasing.
Therefore increases stability by donating electron.
\((3)\) Chlorine is also electron withdrawing but its effect is less than \(-NO_2\) group.
Hence, correct order of stability.
\((4)\)
પ્રકિયા ની અંદર $SbF_5$ એ શું વર્તે છે ?
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - C{H_3}}\limits_I $
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - OC{H_3}}\limits_{II} $
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - C{H_2} - OC{H_3}}\limits_{III} $