Solubility

Learn the models, terms, and applications of solubility.

Lesson 2 of 32 parts Practice Flashcards

1/2

Solubility and Saturation

Objective: Read limits under stated conditions.

Solubility describes how much solute can dissolve in a specified amount of solvent at a given temperature and, for gases, pressure. An unsaturated solution is below its equilibrium limit, a saturated solution is at that limit, and a supersaturated solution exceeds the usual equilibrium amount and can be unstable. A solubility curve reports an equilibrium amount, not how quickly the solute dissolves. For a solid with solubility 30 g per 100 g water at a given temperature, adding 40 g to 100 g water leaves about 10 g undissolved at equilibrium if no other interactions change the limit. Solubility varies by solute and solvent; “like dissolves like” is a rough polarity guide, not a universal law.

Worked examples

Try itIf solubility is 30 g per 100 g water and 40 g is added, about how much stays undissolved?Show answer

1. Identify the relevant concept in this section. 2. At equilibrium 30 g can dissolve and ten remain. 3. Answer: 10 g

Swipe sideways to move between sections

Solubility and Saturation

Objective: Read limits under stated conditions.

Worked examples

Try itIf solubility is 30 g per 100 g water and 40 g is added, about how much stays undissolved?Show answer

1. Identify the relevant concept in this section. 2. At equilibrium 30 g can dissolve and ten remain. 3. Answer: 10 g

Applications and Worked Problems

Objective: Apply solubility to calculations, evidence, and specified situations.

Solubility is an equilibrium amount under stated conditions, not how quickly something dissolves. Scale a value expressed in grams per 100 g solvent by the actual solvent mass. Saturated solutions reach the specified equilibrium limit; any extra solid may remain undissolved. Stirring and smaller particles often speed dissolution without changing the final solubility at the same conditions. Temperature effects depend on the substance; dissolved gases commonly increase with gas partial pressure at fixed temperature.

Formulas

maximum mass = stated g per 100 g solvent × solvent mass/100

Worked examples

Try itAt a stated temperature, solubility is 20 g per 100 g water. What maximum mass dissolves in 100 g water?Show answer

1. Scale the stated solubility by water mass. 2. 20×100/100=20 g.

Try it30 g solute is added to 100 g water, with solubility 20 g/100 g water. At equilibrium, how much remains undissolved?Show answer

1. Maximum dissolved mass is 20 g. 2. Excess=30−20=10 g.

You finished the reading!

Lock it in with a few practice questions, then move on to the next lesson.

Practice Next lesson

Previous lessonConcentration Next lessonpH and Neutralization