As chemical reactions are predominantly driven by the movement of electrons between various species, the property of electronegativity becomes extremely important in understanding how key atoms and molecules participate in reactions.

Electronegativity is defined as the tendency of an atom or group to attract electrons towards itself. As a result, atoms with different electronegative properties would naturally function differently in reaction, and it is very often related to kinetics especially when involving charged molecules as intermediates in reactions.

Consider the two-step substitution reaction between CH₃I and sodium hydroxide (NaOH) shown below. Sodium (Na⁺) is a spectator ion (does not participate in the reaction and only balances the charge, so it has been omitted).

CH₃I + OH^– → CH₃⁺ + I^– + OH^– → CH₃OH + I^–

In the above reaction, CH3⁺ acts as an intermediate and is short-lived molecule with a positive charge on the central carbon atom. The hydrogen atoms which surround this central carbon atom are of roughly the same electronegativity as carbon, therefore they do not act to further increase the positive charge on the carbon; however, surrounding electronegative atoms are often capable of drawing away electrons from the central atom, further increasing positive charge on the central atom. The speed at which the reaction proceeds is dependent on how positive the carbon is; the higher positive charge it has, the faster it can bind to OH^– to form product.
.

Find an error? Take a screenshot, email it to us at error@mytestingsolution.com, and we’ll send you $3!