Is the solubility of acetic acid, CH3COOH, greater in water or benzene, C6H6?

Name: Chemistry
Author: McMurry
ISBN: 9781292336145

Verified step by step guidance

Step 1: Identify the nature of acetic acid (CH3COOH). Acetic acid is a polar molecule due to the presence of the carboxyl group (-COOH), which can form hydrogen bonds with other polar molecules.

Step 2: Analyze the solvent water (H2O). Water is a highly polar solvent and is capable of forming hydrogen bonds due to its polar O-H bonds.

Step 3: Consider the solvent benzene (C6H6). Benzene is a nonpolar solvent, characterized by its symmetrical ring structure and lack of polar bonds.

Step 4: Apply the principle 'like dissolves like'. Polar solutes tend to dissolve well in polar solvents, while nonpolar solutes dissolve better in nonpolar solvents.

Step 5: Conclude based on the polarity. Since acetic acid is polar and water is polar, acetic acid is more soluble in water than in benzene, which is nonpolar.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Polarity and Solubility

The principle of 'like dissolves like' states that polar solvents dissolve polar solutes, while nonpolar solvents dissolve nonpolar solutes. Water is a polar solvent due to its bent molecular shape and the presence of a significant electronegativity difference between oxygen and hydrogen. In contrast, benzene is a nonpolar solvent, which affects the solubility of substances like acetic acid.

Hydrogen Bonding

Acetic acid can form hydrogen bonds due to the presence of a hydroxyl (-OH) group. This ability to engage in hydrogen bonding significantly enhances its solubility in polar solvents like water, where such interactions can occur. In nonpolar solvents like benzene, acetic acid cannot form these interactions, leading to lower solubility.

Molecular Structure of Acetic Acid

Acetic acid (CH3COOH) has a carboxylic acid functional group, which contributes to its polar nature. The presence of both a hydrophobic methyl group (CH3) and a hydrophilic carboxyl group (COOH) influences its solubility. The polar carboxyl group interacts favorably with water, making acetic acid more soluble in water than in nonpolar solvents like benzene.