Electromeric effect is:
A. Permanent effect, observed in organic compounds.
B. Temporary effect, observed in organic compounds.
C. Both temporary effect and permanent effect.
D. None of these.

Hint: Organic compounds are those compounds which contain carbon along with other elements which are essential for the reproduction of living organisms. Carbon is the main factor in organic compounds as it has four electrons that can accommodate eight electrons in an outer shell. As a result a number of bonds can be formed with other carbon atoms.

Complete Solution :
Due to complete transfer of shared pi electron pairs to other atoms under the presence or we can say due to the influence of an attacking reagent an instantaneous dipole formed in the molecule of any organic compound. This dipole effect is known as electromeric effect. This effect can be observed in only those organic compounds which contain at least one multiple bond. When the atoms participating in this multiple bond come under the effect of an attacking reagent then one pi bonding pair of electrons is completely transferred to one of the two atoms.
- The electromeric effect is a temporary effect that remains as long as the attacking reagent is present and exposed to the organic compound and once this attacking reagent is removed from the system then the molecule which was in polarized nature goes back to its original state.

So, the correct answer is “Option B”.

Note: Electromeric effect is of two type’s known as +E effect and –E effect. +E occurs when the electron pair of the pi bond is moved towards the attacking reagent and this can be observed in the addition of acid to alkenes while –E effect occurs when the electron pair of the pi bond is moved away from the attacking reagent.