Solvents for Liquid-Liquid Extraction

Which solvents are not suitable for liquid-liquid extraction of an aqueous layer?

1. Ethyl Acetate
2. Acetonitrile
3. Diethyl Ether
4. Ethanol
5. Toluene
6. Dichloromethane

A) Ethyl Acetate, Toluene, and Diethyl Ether
B) Ethyl Acetate, Acetonitrile and Dichloromethane
C) Diethyl Ether and Toluene
D) Acetonitrile and Dichloromethane
E) Acetonitrile and Ethanol

Answer:

The solvents that are not suitable for liquid-liquid extraction of an aqueous layer are Acetonitrile and Ethanol.

To determine the solvents that are not suitable for liquid-liquid extraction of an aqueous layer, we need to identify the solvents that are immiscible or have low solubility in water. These solvents should form a separate layer when mixed with water, allowing for the extraction of compounds between the two phases.

1. Ethyl Acetate: Ethyl acetate is suitable for liquid-liquid extraction and is commonly used in this process.

2. Acetonitrile: Acetonitrile is a polar aprotic solvent that can mix well with water and is frequently used in liquid-liquid extractions.

3. Diethyl Ether: Diethyl ether is an organic solvent that is immiscible with water and commonly used for liquid-liquid extraction.

4. Ethanol: Ethanol is miscible with water, meaning it forms a homogeneous solution, so it is not suitable for liquid-liquid extraction of an aqueous layer.

5. Toluene: Toluene is an organic solvent that is immiscible with water and commonly used in liquid-liquid extraction.

6. Dichloromethane: Dichloromethane (also known as methylene chloride) is an organic solvent that is immiscible with water and frequently used in liquid-liquid extractions.

Based on this information, the solvents that are not suitable for liquid-liquid extraction of an aqueous layer are Acetonitrile and Ethanol.

Therefore, option E) "Acetonitrile and Ethanol" is the correct answer.