Question

One of the group $ - OC{H_3}$​ is :
A. Stronger +R group than -OH
B. Weaker +R group than -OH
C. Weaker +I group than -OH
D. Inert group

Answer 1

Hint – In order to solve this problem you need to consider the lone pair of electrons present over the group $ - OC{H_3}$ and give the answer.

Step By Step solution:
Groups having negative charge or at least one lone pair of electrons and donate electrons to the benzene ring show resonance effect. Resonance effect is the delocalization of $\pi $ electrons. $ - OC{H_3}$​ group has a weaker +R group than −OH. In −OH group lone pair of Oxygen are easily available which in $−OCH_3$​ group, the path is hindered due to $CH_3$​ group or it can be the +I effect of $CH_3$​ group on oxygen atom that is little unstable than −OH group.
So, $ - OC{H_3}$ is a weaker +R group than –OH.
Hence, the right option is B.

Note – We need to know that in chemistry, resonance is a way of describing bonding in certain molecules or ions by the combination of several contributing structures. If the atom or group is attached to the carbon atom chain it is called electron releasing or +I effect. The inductive effect in chemistry is an experimentally observable effect of the transmission of charge through a chain of atoms in a molecule by electrostatic induction. Knowing this will help you in most of the problems like this.