What is a solution?
A solution is a mixture in which one substance is completely dissolved in another. It looks clear and uniform, and the dissolved particles cannot be seen or filtered out. A common example is sugar dissolved in water.
Every solution has two parts:
- The solute is the substance that dissolves, for example sugar or salt.
- The solvent is the substance that does the dissolving, usually water.
Key idea
Solute + solvent = solution. Water is called the universal solvent because it dissolves so many substances.
Solubility
The solubility of a substance is the maximum amount that can dissolve in a fixed amount of solvent at a certain temperature. When no more solute can dissolve, the solution is said to be saturated. Different substances have different solubilities in water.
Rate of solubility
The rate of solubility is how fast a solute dissolves. It can be increased in three main ways:
- Stirring — moving the solvent brings fresh solvent to the solute.
- Heating — a higher temperature makes particles move faster.
- Crushing — smaller pieces have a larger surface area touching the solvent.
Remember
- Rate of solubility is about how FAST a solute dissolves.
- Solubility is about HOW MUCH can dissolve.
- Stirring, heating and crushing all speed up dissolving.