Problem 15 - Chemistry An Atoms First Approach

Question

List some ways one can increase the solubility of a salt in water.

Step-by-Step Solution

Answer

One can increase the solubility of a salt in water by increasing the temperature, stirring the solution, using smaller salt particles, and adding other solutes to the water (if applicable).

Step 1: 1. Temperature

Increasing temperature usually increases the solubility of a salt in water. This is because when temperature is raised, the water molecules move faster and have more kinetic energy, which helps to dissolve the salt more effectively. The increased energy also allows for the breaking of more ionic bonds in the salt and this results in higher solubility.

Step 2: 2. Pressure

Although pressure has a significant effect on the solubility of gases in water, it usually has little to no effect on the solubility of salts in water. This is because salts are ionic compounds and their solubility depends mainly on the electrostatic interactions between their ions and water molecules. These interactions are not greatly influenced by changes in pressure, especially in comparison to the effects of temperature.

Step 3: 3. Stirring

Agitating the water by stirring can also help to increase the solubility of a salt. Stirring improves the contact between the salt particles and the water molecules, promoting the dissolution process. This is because stirring distributes the dissolved salt particles more evenly in the water and brings fresh solvent into contact with the undissolved salt, effectively speeding up the dissolution process.

Step 4: 4. Using smallest particle size possible

When the salt particles are smaller, they have a larger surface area in contact with the water molecules. This increased surface area helps the water molecules to interact and break the ionic bonds in the salt, leading to faster dissolution and increased solubility.

Step 5: 5. Adding other solutes

Sometimes, adding another solute to the water can help increase the solubility of the salt indirectly. This works through a process called the common-ion effect. If the added solute has an ion in common with the salt, it can compete with the salt for water molecules, effectively reducing the formation of solid precipitates and increasing the solubility of the salt. In conclusion, to increase the solubility of a salt in water, one can increase the temperature, stir the solution, use smaller salt particles, and add other solutes to the water (if applicable).