Chapter 10, Problem 10A.1E

Interpretation Introduction

Interpretation:

The molar potential energy of interaction between singly charged positive and negative ions that are separated by $\text{50}\text{nm}$ in water has to be determined.

Concept introduction:

Polar molecules are the molecules having a positive and negative end and so there will be a charge separation.

A polar molecule is a molecule where the polar bonds are asymmetrically arranged (the dipoles do not cancel)

A nonpolar molecule is a molecule with no polar bonds or a molecule where the polar bonds are symmetrically arranged.

In polar molecule the charge separation occurred with respect to the difference in electronegativity of atoms in the molecule.

Interaction between partial charges:

$\begin{array}{l}\text{V}\left(\text{r}\right)\text{=}\frac{{\text{Q}}_{\text{1}}{\text{Q}}_{\text{2}}}{\text{4πεr}}\\ \\ {\text{Q}}_{\text{1}}\text{and}{\text{Q}}_{\text{2}}\text{-}\text{Charges}\\ \text{r-}\text{Separation}\\ \text{ε}\text{-}\text{Permittivity}\text{of medium}\\ \end{array}$

$\begin{array}{l}\text{ε}\text{=}{\text{ε}}_{\text{r}}{\text{ε}}_{\text{0}}\\ \\ {\text{ε}}_{\text{r}}\text{-}\text{Relative}\text{permittivity}\\ {\text{ε}}_{\text{0}}\text{-}\text{Vacuum}\text{permittivity}\\ \end{array}$