Ester Synthesis Lab

During the Ester Synthesis Lab, we mixed different acids and alcohols together and then heated them in water. We were trying to see what mixtures of acids and alcohols made certain smells when heated. We found that the mixture/heating of acids and alcohols produces a sweet smell. 

We started by mixing 10 drops of isopentyl alcohol with 10 drops of glacial acetic acid and one drop of concentrated sulfuric acid together. This mixture smelled like sweet apple medicine before we heated it, and smelled like dry erase marker/fake banana after we heated it.

The next mixture we did was with 10 drops of ethyl alcohol, 10 drops of glacial acetic acid, and one drop of concentrated sulfuric acid. This mixture smelled like vinegar before we heated it, and then nail polish remover after we heated it. 

The last mixture we did was with 0.15 grams of salicylic acid, 12 drops of methyl alcohol, and 3 drops of concentrated sulfuric acid. This mixture smelled like sweet vinegar before we heated it. Before we could smell the mixture after it was heated, we had to add a few drops of water to the mixture. After we heated it and added the drops of water, it smelled minty.

 

Here is a picture of the test tubes heating in water:

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Here is a picture of my data table:

Questions:

Compare the odors of the three mixtures after heating compared to the odors of the starting materials. How are they different? 

In the beginning, the acids all smelled like vinegar and the alcohol smelled medical. After being combined, the mixtures smelled like vinegar, sweet apple medicine, and sweet vinegar. After heating the mixtures, the mixtures' smell became sweeter and turned to dry erase marker/fake banana, nail polish remover, and mint. The chemical makeup of the sweet smells is different than the makeup of the sour and medicinal smells. The combination of alcohols and acids with heat caused a reaction to occur that produced different functional groups from what the substances started with.

Based on the smell of the mixtures after heating, what functional group must be present in the final molecules that were produced? 
The sweet smell of the mixtures after heating indicates that ester must be present in the final molecules. This functional group is what caused the final products to smell sweet. 

Here is a picture of ester:

Were the new compounds easily identified as a specific fragrance like apple or banana? In the case where a specific fragrance was detected, how does the odor compare to the natural fragrance?
Each person had a different idea of what each substance smelled like because smell is a qualitative description of a substance, not a quantitive one. Each person has been exposed to certain smells more often than others in their lifetime, so they have different ideas on what things smell like and how fast they can identify a scent. One person could be confident in saying that something smells like banana, and not be wrong, while at the same time someone else could say that it smells like an apple, and again, not be wrong. For me, I needed to smell only once to figure out what each substance smelled like because I am very sensitive to strong scents and the substances had very strong scents. The smells from the synthesis reaction smelled the same as the natural fragrance it was identified as which I thought was pretty cool, because we had made these scents ourselves instead of just smelling something that was already made. 

Here is a picture of the finished challenge puzzle: