Question

In $\text{ C}{{\text{H}}_{\text{3}}}\text{C}{{\text{H}}_{\text{2}}}\text{OH }$ , the bond that undergoes heterolytic cleavage most readily is:
A) $\text{ C}-\text{C }$
B) $\text{ C}-\text{O }$
C) $\text{ C}-\text{H }$
D) $\text{ O}-\text{H }$

Answer 1

Chemical reaction involves the breakage of existing bonds and the formation of new bonds. The heterolytic bond fission is bond fission between the two non identical species. The heterolytic bond is as shown below,

The heterolytic cleavage depends on the electronegativity of the species.Element with high electronegativity gains the electron pair.

Complete step by step answer:
-Chemical bonds can be a break in multiple ways. These are as: homolytic bond fission and heterolytic bond fission. Heterolytic fission is bond fission in which the covalent bond between the chemical species is broken unequally.
-The most electronegative species acquire the electron pair from the covalent bond and become the negatively charged known as the anion and other as the positive charge primarily known as a cation.
-Ethanol,$\text{ C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{O}-\text{H }$ have three chemical species in it.This are carbon C, hydrogen H, and oxygen O. The oxygen has more electronegative elements than carbon followed by hydrogen. The increasing order of the electronegativity of C, O, and H is as shown below,
$\text{ H }<\text{ C }<\text{ O }$
There are three kinds of bonds in ethanol. These are $\text{ C}-\text{H }$ ,$\text{ C}-\text{O }$and $\text{ O}-\text{H }$. The trend of the electronegativity difference in the three bonds is as shown below,
$\text{ H}-\text{C }<\text{ C}-\text{O }<\text{ O}-\text{H }$
The $\text{ C}-\text{H }$ bond has the least electronegativity difference followed by $\text{ C}-\text{O }$and $\text{ O}-\text{H }$ has the highest electronegativity difference. This $\text{ O}-\text{H }$ easily undergoes the heterolytic cleavage and forms the ions.

Thus, the $\text{ O}-\text{H }$ bond easily undergoes the heterolytic cleavage.

Hence, (D) is the correct option.

Note: Note that the $\text{ C}-\text{C }$ bond does not undergo the heterolytic cleavage. The heterolytic fission is possible only when the atoms have the electronegativity difference. The $\text{ C}-\text{C }$ bond does not have electronegativity difference, thus instead of heterolytic fission the $\text{ C}-\text{C }$ undergoes homolytic fission and forms radicals.