Chapter 7, Problem 6STP

Interpretation Introduction

Interpretation:

The correct answer is to be identified if a compound is discovered to have a melting point $-100°\text{C}$.

Concept introduction:

The melting point is defined as the temperature at which the substances changes from solid to liquid. The melting of ionic compounds needs the addition of greater amounts of energy in order to break the ionic bonds.

Answer to Problem 6STP

Option C is the correct answer.

Explanation of Solution

Reason for correct option:

Covalent bonds can be either polar or nonpolar and both type of bonds contain a broad range of melting points. Therefore, a compound with a melting point can have either polar covalent bond or nonpolar covalent bond.

Conclusion

Reason for incorrect option:

Option A is incorrect answer. Ionic compounds are solids at room temperature it do not melt until the higher temperature is reached as oppositely charged ions are closely bind with strong attractions. Thus, it does not have ionic bonds.

Option B is also incorrect answer because covalent bonds can be polar and nonpolar and to conclude this compound is polar covalent bond with little additional information is premature conclusion.

Option D is also incorrect answer. Because it cannot have an ionic bondif the melting point is $-100°\text{C}$.