13.2 The Solution Process

Factors Affecting the Rate of Dissolution1. Increasing the surface area2. Agitating the solution3. Heating the solventSolubility:

There is a limit to the amount of solute that is dissolved by a solvent.Saturated solutions: a solution that

contains the maximum amount of dissolved solute

• Unsaturated Solution: a solution that contains less solute than a saturated solution under the existing conditions.

• Supersaturated Solutions: a solution that contains more dissolved solute than a saturated solution under the same conditions

• The solubility of a substance is the amount of that substance required to form a saturated solution with a specific amount of solvent at a specific temperature.

Solute-Solvent Interactions:• “like dissolves like” is a good example for

determining if substances will dissolve one another.

• Ionic compounds:• The polarity of water causes the

charged ends to attract the ions of the ionic compound, and surrounds them so they separate from the other ionic molecules.

• This process with water is called hydration.

• Nonpolar Solvents:• Ionic compounds are not usually

soluble in nonpolar solvents.• Liquid solutes and solvents that are

not soluble in each other are called immiscible.

• Liquids that dissolve freely in one another are called miscible.

• Pressure and solubility:• Pressure has very little effect on the

solubility of liquids• However, an increase in pressure

increases gas solubility in liquids (CO2 in coke)

• Henry’s Law:• The solubility of a gas in a liquid is

directly proportional to the partial pressure of that gas on the surface of the liquid.

• Temperature and Solubility:• Increasing temp usually decreases

gas solubility.• Increasing temp usually increases

solid’s solubility.• Heat of Solution:• The net amount of heat energy

absorbed or released when a specific amount of solute dissolves in a solvent is the heat of solution.