Homogeneous Mixture — Definition & Examples

Written by

Malcolm McKinsey

January 12, 2023

Fact-checked by

Paul Mazzola

Homogeneous mixture definition

A homogeneous mixture is a mixture of substances blended so thoroughly that you cannot see individual substances. Every sample of the mixture will show the same amounts of each substance. Homogeneous mixtures can be solid, liquid, gas, or plasma mixtures.

Properties of homogeneous mixtures

Homogeneous mixtures have several identifying properties:

1. Homogeneous mixtures that are thoroughly mixed down to the level of molecules are called solutions.

2. Homogeneous mixtures exist in one phase of matter at a time. You will not see liquid water and solid water together in a homogeneous mixture. That means your glass of ice water, with ice cubes floating in it, is a heterogeneous mixture of homogeneous mixtures.

3. Homogeneous mixtures cannot be expressed as chemical formulas.

4. To describe any homogeneous mixture accurately, you need to name the components and tell their proportion or ratio within the mixture.

5. Like all mixtures, homogeneous mixtures can be separated into their components, usually by taking advantage of their physical properties such as boiling point or magnetism.

Saltwater is an example of a homogeneous mixture that can be easily separated by evaporation.

Many countries use evaporation to capture pure drinking water from seawater, leaving behind salt that can be sold for profit.

Sugar water is another example of a homogeneous mixture that can be separated by evaporation.

Homogeneous compound

A mixture is not a compound. In chemistry, pure substances can be chemically bonded to form compounds. If the substances do not chemically bond, they form mixtures.

An example of a homogeneous compound is pure water (${H}_{2}O$). The hydrogen is bonded to the oxygen.

Carbon dioxide is another example of a homogeneous compound.

However, the air you are breathing is a homogeneous mixture. Every breath is an equal mix of nitrogen, oxygen, argon, carbon dioxide, water vapor, and some other substances.

Homogeneous vs. heterogeneous mixture

In chemistry, we can have two types of mixtures: homogeneous mixtures and heterogeneous mixtures:

• Homogeneous mixture are blended so thoroughly, it looks like one substance – Uniform composition.

• Heterogeneous mixture are not thoroughly blended, so you can see and pick out an individual part of the mixture.

Before really digging into these mixtures, let's learn to say them correctly. These are five- and six-syllable words:

• Homogeneous: ho-mo-gee-nee-us

• Heterogeneous: het-er-oh-gee-nee-us

Both words are adjectives, not nouns. You have to use them to describe something else, like a mixture. You can't say, "This is a heterogeneous."

The prefix "homos" means "same," while the prefix "hetero" means "different." The root of "geneous" is a Greek word, "genos," meaning a group, type, or stock. So, homogeneous means all the same group, and heterogeneous means all different groups together.

Think of two different bowls of soup: tomato soup is homogeneous, while vegetable soup is heterogeneous.

Here are three more examples of heterogeneous mixtures:

• Students in a classroom

• Trail mix

• A load of laundry

Homogeneous mixtures examples

If you carefully look around your own home, you can see many examples of homogeneous mixtures in your house.

Here is a list of household homogeneous mixtures:

• Window cleaner

• Lotion

• Liquid soap

• Milk

• Hand sanitizer

• Soft drinks

• Lemonade (if you strain out all seeds and pulp)

Those might have seemed obvious. Consider these, too:

• Tapwater (only laboratory-grade water is a compound; most water has dissolved gases and solids in it)

• The clay and graphite in a wood pencil "lead."

• Ink in a pen

• Cement (not be confused with concrete)

• Plastics

• Gasoline

• Candles

• Metal cans

• Liquid dishwasher or laundry detergent

These are all mixtures that are uniform throughout when viewed with the naked eye.

Never taste, touch, or smell chemicals at home or in a science laboratory. You can look at some items and see immediately that they are homogeneous mixtures. Everything is blended, and you cannot pick out any one item in the mixture.

Homogeneous mixtures quiz

Test your knowledge of homogeneous mixtures by answering these questions:

1. What is the definition of a homogeneous mixture?

2. Is a cup of coffee a homogeneous mixture?

3. What does a homogeneous mixture look like?

4. Is a solution a homogeneous mixture?

5. Of the choices below, which are homogeneous mixtures?

   1. A bag of trail mix

   2. Air

   3. Italian salad dressing (oil, spices, and vinegar)

   4. A chocolate milkshake

   5. Seawater

   6. A steel bridge

Don't get mixed up! Do the work first, then check your answers below.

1. The definition of a homogeneous mixture is one that is mixed so thoroughly that you cannot see the individual components or parts.

2. Brewed coffee is a homogeneous mixture.

3. A homogeneous mixture looks like all one thing, even though it is made up of different components. Air is invisible; seawater is a liquid that looks clear; the steel legs of a classroom chair are made from an alloy, a homogeneous mixture.

4. Yes, a solution is a homogeneous mixture. An example of a homogeneous solution is a soft drink.

5. Choices 1 and 3 are not homogeneous mixtures. 2, 4, 5, and 6 are homogeneous mixtures:

   1. A bag of trail mix

   2. Air

   3. Italian salad dressing (oil, spices, and vinegar)

   4. A chocolate milkshake

   5. Seawater

   6. A steel bridge