Chapter 8, Problem 123A

Use Lewis structures to predict the molecular polarities for sulfur difluoride, sulfue tetrafluoride, and sulfur hexafluoride.

Interpretation Introduction

Interpretation:

The molecular polarities for sulfur difluoride, sulfur tetrafluoride, and sulfur hexafluoride are to be determined.

Concept introduction:

The asymmetric structure and presence of polar covalent bonds confirms that the molecule is polar in nature. The molecule having some dipole moment is termed as polar molecule and the molecule with no dipole moment or zero dipole moment is identified as nonpolar molecule.

Answer to Problem 123A

The sulfur difluoride and sulfur tetrafluoride are polar, but sulfur hexafluoride is nonpolar.

Explanation of Solution

The given molecule sulfur difluoride $\left({\text{SF}}_{\text{2}}\right)$ has a bent shape and therefore asymmetrical. The structure of ${\text{SF}}_{\text{2}}$ molecule is shown below.

In ${\text{SF}}_{\text{2}}$, the charge distribution at any distance from its center is unequal and different (but not opposite) in direction. Therefore, there is some dipole moment which makes ${\text{SF}}_{\text{2}}$ as a polar compound.

The given molecule sulfur tetrafluoride $\left({\text{SF}}_{\text{4}}\right)$ has a bent shape and therefore asymmetrical. The structure of ${\text{SF}}_{\text{4}}$ molecule is shown below.

In ${\text{SF}}_{\text{4}}$, the charge distribution at any distance from its center is unequal and different (but not opposite) in direction. Therefore, there is some dipole moment which makes ${\text{SF}}_{\text{4}}$ as a polar compound.

The given molecule sulfur hexafluoride $\left({\text{SF}}_{\text{6}}\right)$ has trigonal bipyramidal and therefore symmetrical. The structure of ${\text{SF}}_{\text{6}}$ is shown below.

In ${\text{SF}}_{\text{6}}$, the charge distribution at any distance from its center is equal but opposite in direction. Therefore, the partial charges in ${\text{SF}}_{\text{6}}$ balance which makes ${\text{SF}}_{\text{6}}$ as a non-polar compound.

Conclusion

The sulfur difluoride and sulfur tetrafluoride are polar but sulfur hexafluoride is nonpolar.