Solubility Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Solubility.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

The maximum amount of a solute that can dissolve in a given quantity of solvent at a specific temperature and pressure, typically expressed as grams of solute per 100 mL of solvent. Beyond this limit, additional solute remains undissolved.

How much can dissolve before no more will. Sugar: high solubility. Sand: zero.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Solubility depends on the nature of solute/solvent, temperature, and pressure (for gases).

Common stuck point: 'Like dissolves like'—polar solutes dissolve in polar solvents.

Sense of Study hint: When predicting solubility, apply the 'like dissolves like' rule. First determine if the solute is polar, nonpolar, or ionic. Then match it with a solvent of similar polarity. Finally, check a solubility table or curve for the specific temperature, as most solid solubilities increase with temperature while gas solubilities decrease.

Worked Examples

Example 1

easy
Define solubility and explain how temperature generally affects the solubility of solids and gases in water.

Solution

  1. 1
    Solubility is the maximum amount of solute that dissolves in a given amount of solvent at a specific temperature, usually expressed in \text{g/100 g water} or \text{g/L}.
  2. 2
    For most solid solutes: solubility increases with increasing temperature (e.g., sugar dissolves faster in hot water).
  3. 3
    For gaseous solutes: solubility decreases with increasing temperature (e.g., warm soda goes flat because dissolved \text{CO}_2 escapes).

Answer

\text{Solids: solubility increases with T. Gases: solubility decreases with T.}
Temperature affects the kinetic energy of particles. For solids, higher temperature helps overcome the lattice energy holding the solid together. For gases, higher temperature gives gas molecules enough energy to escape the liquid.

Example 2

medium
Using a solubility curve, determine how many grams of \text{KClO}_3 can dissolve in 100 g of water at 80°\text{C} if the solubility is 40\,\text{g/100 g water}. If the solution is cooled to 30°\text{C} where the solubility is 10\,\text{g/100 g water}, how much crystallizes out?

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

medium
At 25°\text{C}, the solubility of \text{CaSO}_4 is 0.21\,\text{g/100 mL}. If a student adds 1.0 g of \text{CaSO}_4 to 200 mL of water, will it all dissolve? How much remains undissolved?

Example 2

hard
Explain why a scuba diver must ascend slowly, using the concept of gas solubility and Henry's Law. What happens to the dissolved nitrogen in the diver's blood as pressure decreases?
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Related Concepts

Solution

Background Knowledge

These ideas may be useful before you work through the harder examples.

solution