Question

trick to remember positive mesomeric (+M) and (-M) effect chart .

Please
Jee friends

Answer 1

Hey mate see attachment .

Answer 2

We generally see Mesomeric effect in Benzene.

#Trick

When electrons, lone pair move towards benzene, it is + M effect.

When electrons, lone pair move away from benzene, it is - M effect.

$<b><u>- M effect can be seen when benzene attached with following groups –</b></u>$

$\sf{- OH, \ - NO_2, \ - NC, \ - OHC, \ - OOCH,}$
$\sf{- X}$

$<b><u>+ M effect can be seen when benzene attached with following groups –</b></u>$

All metals and alkyl groups like Me, Et, Pr etc.