Chapter 8.4, Problem 30SP

Interpretation Introduction

Interpretation: The given covalent bonds need to be arranged in order from least to most polar.

Concept Introduction: A bond is polar if there is an electronegativity difference between the atoms bonded together. Here, the atom with high electronegativity will have a partial negative charge, and the atom with low electronegativity will have a partial positive charge. The strength of the polarity of a bond depends on the magnitude of the difference in electronegativity between two atoms.

Answer to Problem 30SP

  $\text{H}-\text{C}<\text{H}-\text{S}<\text{H}-\text{Br}<\text{H}-\text{Cl}$

Explanation of Solution

In the options, the hydrogen atom is bonded with different atoms of an element such as chlorine, bromine, sulfur, and carbon. Here, the hydrogen atom is the same; thus, the difference depends on the electronegativity of other atoms. On comparing the electronegativity, chlorine is the most electronegative and carbon is the least electronegative. The order of electronegativity is as follows:

  $\text{C}<\text{S}<\text{Br}<\text{Cl}$

Conclusion

Therefore, the order from least to most polar covalent bond will be:

  $\text{H}-\text{C}<\text{H}-\text{S}<\text{H}-\text{Br}<\text{H}-\text{Cl}$