Question

1. We used the technique of extraction in this lab. After extraction, what was left in solution? Why is it acceptable for those chemicals to be left to sit for a week? Think about the possible reactions that would or would not occur during the week?
   1. In our extraction, we used NaCl solution. Why did we choose to use that vs. water?

In this experiment, we did a Fischer Esterification using excess acetic acid, isopentyl alcohol, and sulfuric acid to form isopentyl acetate. Sodium bicarbonate was then used for extraction along with the NaCl solution. Thanks in advance for the help.

Answer 1

Saturated NaCl solution when we used in extraction it pulls the water from the organic layer. It is because of concentrated solutions want to become dilute solutions(osmosis low to high concentration) and also NaCl breaks the emulsions formed during the extraction.

The reaction does not favor the esterification because water is forming in reaction, it can shift the reaction backward. According to Le chatelier's principle the equilibrium shits forward direction if increase concentration of any the reactant.  Excess acetic acid can use because it is cheap and also easy to separate compare to isopentyl alcohol.

Sodium bicarbonate is used to remove sulfuric acid and excess acetic acid . it reacts with the acid , neutralizes and forms water-soluble sodium acetate, sodium sulfate, and carbonic acid.

After extraction solution contents are left for one week because it libarate some hazards chemicals and gases.

After extraction solution contains sodium acetate, it dissolves in water and produces acetic acid.

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