I don't understand the answer of this organic chemistry multiple choice question?

When the compounds below are listed in order of decreasing boiling point (highest to lowest) what is the correct order?

1. ethane 2. fluoroethane 3. ethanol 4. ethanoic acid

A. 4,3,1,2
B. 4,3,2,1
C. 3,4,1,2
D. 2,1,3,4

Why is the correct answer B? Please explain. Thanks!

Ethanol and ethanoic acid have hydrogen bonding so they have much higher boiling points than the other two.

ethanoic acid has a higher molar mass than ethanol so I would expect ethanoic acid to have the highest boiling point.

Ethane is C2H6
Fluoroethane is C2H5F. Since F is much more massive than H, I would expect Fluoroethane to have a higher boiling point than ethane.

When you look up each compound, that is the order from highest to lowest boiling points.
4. ethanoic acid = 118 C
3. ethanol = 78 C
2. fluoroethane= 32 C
1. ethane= - 88.5 C

If you would have looked this up yourself, you could have figured this out yourself.

1) The relative strength of the four intermolecular forces is: Ionic > Hydrogen bonding > dipole dipole > Van der Waals dispersion forces. The influence of each of these attractive forces will depend on the functional groups present.
2)Boiling points increase as the number of carbons is increased.
3)Branching decreases boiling point.
So, ethanol and ethanoic acid contain hydrogen bonding--> have higher boiling points

Also, as the molecular weight of compound increases, so does it boiling point so that why fluoroethane is next cuz it has a bigger molecular weight than ethane

ethane has only London forces or Van der Waals dispersion forces and has the smallest molecular weight that why it has the lowest boiling point

hope that helps