What is a Solution in Science? – Definition & Examples

What Is a Solution?

A solution is a type of homogeneous mixture that is made up of two or more substances. A homogeneous mixture is a type of mixture with a uniform composition. This means that the substances cannot be distinguished easily from one another.

Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. When you look closely, upon mixing salt with water, you can’t see the salt particles anymore, making this a homogeneous mixture.

Let’s make use of our salt water example to talk about the two main parts of a solution. These are:

• Solute: this is the substance that makes up the minority of the solution, or this is the part that is dissolved. In our example of salt water, the solute is the salt.
• Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved. In our example of salt water, the solvent is water.

When we think about solutions, the first thing we think about is a substance dissolved in water. This is natural because after all, water is the universal solvent. However, solutions are not limited to the liquid phase. Solutions can exist in the gaseous phase – the air we breathe is a solution that is composed of a mixture of gases. Solutions are also present in the solid phase – brass is a solid solution that is a mixture of copper and zinc. In the next section, we’ll discuss what the different types of solutions are in different phases.

Types of Solutions – Solid, Liquid, and Gas

Solutions exist in solid, liquid, and gas phases with different combinations. The solute and the solvent mix completely and evenly, so these are still classified as solutions. Here are the different types of phase combinations with examples for each:

Solid solutions: the solvent is solid

• Solid – solid: A solid solute is mixed with a solid solvent. Examples are brass, which is composed of zinc and copper, and steel, which is composed of carbon and iron.
• Gas – solid: A gas solute in a solid solvent. An example is hydrogen (solute) dissolved in palladium (solvent).

Liquid solutions: the solvent is liquid