Chapter 8, Problem 119A

Interpretation Introduction

Interpretation:

The most polar bond needs to be identified.

1. C-O b. Si-O, c. C-Cl d. C-Br

Concept introduction:  Electronegativity is the comparative strength of an atom to pull electrons in a chemical bond. The character and type of a chemical bond can be predicted employing the electro negativity difference of the elements that bond.

Answer to Problem 119A

The most polar bond is Si-O.

Explanation of Solution

Electronegativity value of

$\begin{array}{l}\text{O}=3.44\\ \text{C}=2.55\\ \text{Si}=1.90\\ \text{Cl}=3.16\end{array}$

$\text{Br}=2.96$

From the above electro negativity value evaluate the electro negativity difference of each as follows:

Electronegativity difference of C-O is $3.44-2.55=0.89$.

Electronegativity difference of Si-O is $3.44-1.90=1.54$

Electronegativity difference of C-Cl is $3.16-2.55=0.61$

Electronegativity difference of C-Br is $2.96-2.55=0.41$

Electronegativity of Si-O is highest. Hence, the bond between Si and O is most polar.

Conclusion

During a reaction the type of bond formation is related to each atom’s attraction for electrons.