Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: R

There are no items in this cart.
Continue Shopping
Get instant 20% OFF on Online Material.
coupon code: MOB20 | View Course list

Get extra R 500 off



What is +M effect and - M effect. What are its consequences?

6 years ago


Answers : (1)


Dear anurag,

The mesomeric effect or resonance effect  is a property of substituents  in a chemical compound. The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M. The mesomeric effect is negative (-M) when the substituent is an electron-withdrawing group and the effect is positive (+M) when based on resonance the substituent is an electron releasing group.

  • Examples of -M substituents: acetyl (IUPAC ethanoyl) 

  • Examples of +M substituents: alcohol - amine

We are all IITians and here to help you in your IIT JEE preparation.

All the best.

 If you like this answer please approve it....

win exciting gifts by answering the questions on Discussion Forum


Sagar Singh

B.Tech IIT Delhi

6 years ago

Post Your Answer

Other Related Questions on Organic Chemistry

what happen in gas convert into liquid when we compress
@ kuldeep i am not getting your query , kindly be specific , when we will compress the gas , then the particles that are there in the gas will come closer with each other and we can...
Umakant biswal one month ago
an alkyl halide, C6H13Cl reacts with potassium tertiary butoxide gives isomeric alkenes Y and Z. both alkenes give2,3- di methyl butane. identyfy y and z?
Please refer to the Askiitians Notes from here:
Vikas TU one month ago
examples for stereo centres which are not chiral centres
Dear student Stereocentre- If there is no plane of symmetry in the molecule of an organic compound, we say it is having a stereocentre. Chiral Centre/Chiral Carbon Atom - If in a moelcule...
Bhavya one month ago
no of geometrical and optical isomers of the compound [co(NH3)2Cl2(en)]+
This is M(AA)a 2 b 2 type compund.I have 3 G.I out of which two are trans which can’t show optical isomerism (O.I) While cis form show O.I hence occur in d & l pair Thus,3G.I & 2 O.I but...
Pranav Dabhade 4 days ago
All over nao2 what is among is. What nao2 separate is also found.
Already answered . Check twice please! NaO2 is called sodium superoxide which is obtained by treating Na2O2 that is sodium peroxide with O2 at high pressures. The Reaction goes like this:...
Vikas TU 14 days ago
Electronic transistion in He + ion takes place from n 1 to n 2 shell such that: 2n 2 +3n 1 =18 2 n 2 -3n1=6 What will be the totalno. of photons emitted when electron transit to n1 shell?
Dear Mudit, Remmeber these two formulaes: 1) Maximum no. of photons they eemits if they return to ground state is: n(n-1)/2 2) And for n2 to n1 level, formmulae is: (n2-n1)(n2-n1+1)/2 gives ...
Vikas TU 3 months ago
By solving I got n1=2 and n2=6 By applying the formula I got the answer 1 while the answer given in book is 10. So help me out with this.
Mudit 3 months ago
Solve both the eqns. and get the value of n1 and n2. Then to know total number of photons to n1 state, Apply the fomulae: n1(n1-1)/2
Vikas TU 3 months ago
View all Questions »

  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: R 15,000
  • View Details
Get extra R 3,750 off

Get extra R 500 off

More Questions On Organic Chemistry

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!!
Click Here for details