What is a Solution in Chemistry?

A solution is much more than an answer to a complicated math problem. It is also a chemistry term! Learn what solutions are, how to identify them, and examples of common solutions!

What are Solutions?

A solution is what occurs when two chemicals are mixed, referred to as a solvent and a solute. The combination of solute and solvent together is a solution. These are often one substance dissolved in another, such as dissolving salt in water, although a solution can be made from any state of matter.

A solute plus a solvent makes a solution
Combining a solute and a solvent makes a solution

Solutions are homogeneous mixtures. Being a homogeneous mixture means they are the same throughout and the particles are evenly distributed. The particles (solute) are usually small (0.1-2 nm) to allow them to be evenly distributed and not settle out.

A solution is different than a mixture or suspension. In solutions, the solute will not settle and precipitate out over time. This is different than a suspension with larger particles that will eventually settle out of the suspension. Paint and aerosol sprays are examples of suspensions.  

Two common terms when talking about solutions are solvent and solute. The solvent is what makes up the majority of the solution. The solvent is often a liquid, such as water. The solute is a substance being dissolved in the solvent, such as salt. There is always less solute than solvent. The solute is the minor component.  (See the article ‘Solute vs Solvent’ for a more in-depth explanation of these terms.)

The properties of the solution are often different than that of just the solute or solvent on their own. For example, ions dispersed in a solvent may change the conductivity. 

When water is the solvent, the mixture is referred to as an aqueous solution.

Types of Solutions

Solutions can be classified by the states of matter of the solute and solvent. Below is a list of the possible combinations of solute in a solvent that form solutions.

  • Gas in gas
  • Gas in liquid
  • Liquid in liquid
  • Solid in liquid
  • Liquid in solid
  • Gas in solid
  • Solid in solid

Examples of Solutions with Explanations

A common example is tea. The solvent is hot water. The solute is all the different chemicals and flavors that come from the tea leaves. The water is dissolving these flavors. Therefore, tea is a solution.

In the chemistry lab, you will commonly make solutions. Whenever you dissolve a sample into a solvent such as water, IPA, or acetone you are making a solution with your sample as the solute.

Air is an example of a gas in gas solution. The main component of air is nitrogen. Mixed into the nitrogen gas are many other gasses such as oxygen (which we breathe) and carbon dioxide (which causes climate change).

Solutions can also be a gas dissolved in liquid. Carbonated water provides a great example of a gas dissolved in a liquid to make a solution. The water is the main component, the solution. Dissolved in the water is carbon dioxide which is the solute and makes the water bubbly.

Carbonated water is an example of a solution
Carbonated water is an example of a solution where the gas is the solute.(Source: Wikipedia Commons)

Gasoline is a common example of a liquid in liquid solution. A combination of liquid hydrocarbons make up gasoline. One of these will be the solvent, with the rest being solutes.

List of Solution Examples

Here is a list of some real-world examples of solutions

  • Soda
  • Tea
  • Metal alloys
  • Seawater
  • Rubbing Alcohol
  • Air
  • Gasoline
  • Mercury with silver (used in dentistry)
  • Sugar in coffee

There are many, many other common solutions that we interact with every day. Try to name a few more!

Solution Vocabulary

  • Aqueous: A solution where the solvent is water
  • Colloid: A solution with large particles that cause opacity.
  • Heterogeneous Mixture: a mixture that has regions of different composition
  • Homogeneous Mixture: a mixture that has uniform composition and properties throughout
  • Solute: The minor component of solutions
  • Solvent: The majority component of solutions
  • States of Matter: The three main forms a chemical can be in—solid, liquid, or gas
  • Suspension: A mixture with large particles that will precipitate over time. Since the suspension is not homogeneous, these are not solutions.