Chapter 16.1, Problem 5LC

Interpretation Introduction

Interpretation: The conditions that determine the solubility of solid, liquid, and gaseous solutes in a solvent need to be explained.

Concept introduction: A solution is a mixture of two or more components and the composition of the mixture is homogeneous. Solute in solvent makes the solution. Different conditions affect the rate of solubility of the solute in the solvent.

Answer to Problem 5LC

The condition that determines the solubility of solid, liquid, and gaseous solutes are pressure and temperature.

Explanation of Solution

The solubility of solid, liquid, and gaseous solutes is affected by conditions and those following:

• Pressure: In the case of solid and liquid, the pressure does not affect the solubility that much but in the case of gas, the pressure affects the solubility to a great extent. The solubility of a gas increases when the partial pressure of a gas above the liquid increases. This solubility of gas can be explained by Henry law such as:

Henry's law states that the solubility of a gas is proportional to its partial pressure. As, the partial pressure of the gas increases, its solubility also increases. This statement can be represented from the equation as:

  $\frac{S1}{P\text{1}}=\frac{S\text{2}}{P\text{2}}$

Where:

• S₁ is the solubility of gas at pressure P_{1 .}
• S₂ is the solubility of gas at pressure P₂ .
• P₁ is the initial pressure.
• P₂ is the final pressure.

From the above equation, it is clear that solubility and pressure are directly proportional to each other. When pressure increases, the solubility of the gas increases and vice versa.

• Temperature: In most of the solid substances, the temperature of the solvent increases then, solubility increases. This is because as the temperature increases, high energy can be provided to break the bonds in solids easily. In the case of gases, the temperature increases then the solubility of gas decreases. This is because high energy is provided to overcome the attraction between the gas molecules and the solvent.

Conclusion

The conditions that determine the solubility of solid, liquid, and gas solutes in solvent are pressure and temperature.