Question

When a small amount of hexanoic acid [CH3(CH2)4CO2H, pKa~4.8], is added to a separatory funnel which contains the organic solvent diethyl ether and water with a pH of 2.0, it is found mainly in the ________ phase as ________.

Answer 1

Answer:

Check explanation.(esp. last part of the Explanation section).

Explanation:

I must confess to you, this question is somehow tricky, but no matter what we are smarter! This question is based on acid base extraction. the organic solvent diethyl ether is the organic base while H2O is the neutral (that is water is acting as a neutral medium). When the hexanoic acid [CH3(CH2)4CO2H is added and mixed with organic solvent diethyl ether and water. The ether which is at the top layer contains the [CH3(CH2)4CO2H and the water which is at the buttom contains [CH3(CH2)4COO- in which a proton is taken away from [CH3(CH2)4COOH through the addition of

So, what is tricky about the question? The fact that there are two media makes it tricky if we go for water phase as [CH3(CH2)4COO- and if we go for ether phase as [CH3(CH2)4COOH, they are both right. So, both are correct but in this question ether phase as [CH3(CH2)4COOH will be appropriate here.