Which order is correct for the decreasing reactivity to ring monobromination of the following compounds `underset(I)(C_(6)H_(5)CH_(3)), underset(II)(C_(6)H_(5)COOH),underset(III)(C_(6)H_(6)),underset(IV)(C_(6)H_(5)NO_(2))`

Options

A. I>II>III>IV
B. I>III>II>IV
C. II>III>IV>I
D. III>I>II>IV

Answer

B

Explanation

Monobromination of the aromatic compound substitution reaction. The electron donating group (like `-CH_(3)`) will increase the reactivity of ring while electron withdrawing groups decrease the reactivity of the ring. Hence, among the given, the reactivity of `C_(6)H_(5)CH_(3)` is highest.
Between `C_(6)H_(5)COOH and C_(6)H_(5)NO_(2)` electron withdrawing power of `-NO_(2)` group is higher than `-COOH`. so, the reactivity of `C_(6)H_(5)COOH` is higher than `C_(6)H_(5)NO_(2).` the decreasing monobromination is `underset((I))(C_(6)H_(5)CH_(3)) gt underset((III))(C_(6)H_(6)) gt underset((II))(C_(6)H_(5)COOH) gt underset((IV))(C_(6)H_(5)NO_(2))`