Why is it easier to remove excess acetic acid from isopentyl acetate than excess isopentyl alcohol?
Sodium Bicarbonate is added but the question doesn't say anything about it.
The addition of sodium bicarbonate is crucial for the removal of excess acetic acid from isopentyl acetate. When excess acetic acid is present, sodium bicarbonate (NaHCO3) can be added to react with the acetic acid and produce carbon dioxide gas (CO2) and water (H2O). This reaction can be represented as follows:
CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O
The carbon dioxide gas bubbles out of the reaction mixture, causing the excess acetic acid to be removed. On the other hand, isopentyl alcohol does not readily react with sodium bicarbonate, so it remains in the reaction mixture. Therefore, it is easier to remove excess acetic acid from isopentyl acetate than excess isopentyl alcohol when sodium bicarbonate is used.
To understand why it is easier to remove excess acetic acid from isopentyl acetate than excess isopentyl alcohol, we need to consider the reaction and the properties of the compounds involved.
Isopentyl acetate is synthesized by the reaction between acetic acid and isopentyl alcohol, commonly known as esterification. The balanced chemical equation for this reaction is:
acetic acid + isopentyl alcohol ⟶ isopentyl acetate + water
To remove excess acetic acid or isopentyl alcohol, we can take advantage of their different solubilities in water, and their different acid-base properties.
Acetic acid is a carboxylic acid and is acidic in nature. It can react with bases, such as sodium bicarbonate (NaHCO3), to produce carbon dioxide gas (CO2), water (H2O), and a corresponding salt:
acetic acid + sodium bicarbonate ⟶ sodium acetate + carbon dioxide + water
Sodium acetate, being a salt, is highly soluble in water. This solubility allows for the removal of excess acetic acid from the mixture, as it will dissolve in the aqueous phase.
On the other hand, isopentyl alcohol is an alcohol and does not readily react with sodium bicarbonate. It is not acidic and does not produce carbon dioxide gas when added to sodium bicarbonate.
Therefore, the addition of sodium bicarbonate primarily helps in removing the excess acetic acid by converting it into a soluble salt. The isopentyl alcohol remains mostly unaffected and does not undergo substantial reaction with sodium bicarbonate. As a result, excess isopentyl alcohol may remain in the mixture and not be as easily separable.
It's important to note that while the question may not specifically mention the addition of sodium bicarbonate, it is commonly used in such processes. Adding sodium bicarbonate is a common step to neutralize excess acid during reactions or to facilitate the separation of acid components from a reaction mixture.