Answer:
1) Ethanol
Explanation:
If we will have <u>interactions</u> we will need more <u>energy</u> to break them in order to go from liquid to gas. If we need more <u>energy</u>, therefore, the <u>temperature will be higher</u>.
In this case, we can discard the <u>propanone</u> because this molecule don't have the ability to form <u>hydrogen bonds</u>. (Let's remember that to have hydrogen bonds we need to have a hydrogen bond to a <u>heteroatom</u>, O, N, P or S).
Then we have to analyze the hydrogen bonds formed in the other molecules. For ethanol, we will have only <u>1 hydrogen bond</u>. For water and ethanoic acid, we will have <u>2 hydrogen bonds</u>, therefore, we can discard the ethanol.
For ethanoic acid, we have 2 <u>intramolecular hydrogen bonds</u>. For water we have 2 <u>intermolecular hydrogen bonds</u>, therefore, the strongest interaction will be in the <u>ethanoic acid</u>.
The<u> closer boiling point</u> to the 75ºC is the <u>ethanol</u> (boiling point of 78.8 ºC) therefore these molecules would have <u>enough energy</u> to <u>break</u> the hydrogen bonds and to past from<u> liquid to gas</u>.
