Which of the following has the highest boiling point?

Question

Which of the following has the highest boiling point?

Select one:

a. CCl₄

b.   NaCl

c.  HBr

d. CH₃CH₂CH₃

Answer 1

CCl4 has dispersion forces as the only intermolecular forces so will have a low b.p.

CH3CH2CH3 also has only dispersion forces, and will also have a low b.p.

That leaves NaCl and HBr.

HBr has hydrogen bonding as well as dipole-dipole forces. But NaCl has strong electrostatic forces as it is an ionic compound. These forces are stronger than dipole and hydrogen bonding, so NaCl will have the highest b.p.