Question

Arrange the following compounds in order from highest to lowest boiling point. Try to do it based on your knowledge of noncovalent interactions, without looking up the actual boiling points.

-CCl4
-dichloromethane (CH2Cl2)
- propane
- 1-butene

Answer 1

To determine the boiling points from lowest to highest, we consider intermolecular forces and molecular masses. Propane, being the lightest, has the lowest boiling point, followed by 1-butene. Dichloromethane and carbon tetrachloride have higher boiling points due to greater molecular masses and, in the case of CH2Cl2, dipole-dipole interactions.

Step-by-step explanation:

To arrange the compounds CCl4 (Carbon tetrachloride), CH2Cl2 (Dichloromethane), propane, and 1-butene in order of increasing boiling points based on noncovalent interactions, we need to consider the types of intermolecular forces present and the molecular mass of the compounds.

Dichloromethane has a higher molecular weight compared to propane and 1-butene, so it should have a higher boiling point due to stronger London dispersion forces. Carbon tetrachloride has even more chlorine atoms and therefore a higher molecular weight and stronger dispersion forces than dichloromethane, leading to the highest boiling point among the four.

However, we need to keep in mind that dipole-dipole interactions in dichloromethane might also play a role due to its polar nature, but typically the greater molecular mass heavily influences the boiling point.

The expected order from lowest to highest boiling point, mainly considering London dispersion forces and partially dipole-dipole interactions, should be:

1. Propane
2. 1-Butene
3. Dichloromethane (CH2Cl2)
4. Carbon tetrachloride (CCl4)