What is the best way to eat a bag of jelly beans? Many people open the bag and eat all the candy, no matter what flavor each piece is. Others pick through the collection. They may say, "I don't like the orange ones." Or maybe they only care for the lemon ones. There are different kinds of jelly beans in the mixture and people will eat what they want and get rid of the rest. A heterogeneous mixture is a mixture in which the composition is not uniform throughout the mixture. Vegetable soup is a heterogeneous mixture. Any given spoonful of soup will contain varying amounts of the different vegetables and other components of the soup. A phase is any part of a sample
that has a uniform composition and properties. By definition, a pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers. Each of the layers is called a phase. In the case of vegetable soup, one phase would be the liquid soup itself. This phase has vitamins, minerals, and other components dissolved in the
water. This phase would be homogeneous. The carrots, peas, corn, or other vegetables represent other phases of the soup.The various vegetables are not mixed evenly in the soup, but are spread around at random. There are a large number of heterogeneous mixtures around us. Soil is composed of a variety of substances, and is often of different composition depending on the sample taken. One shovelful may come up with dirt and grass, while the next shovelful could contain an earthworm. Smog
is another example of a heterogeneous mixture. This murky collection of pollutants can be a mixture of water and contaminants from burning gasoline or plastics, mixed with nitric oxide derivatives and ozone. You can see that the smog distribution in the air illustrated below is not evenly spread out, but varies from one part of the atmosphere to another.Heterogeneous Mixtures
Summary
- A heterogeneous mixture is a mixture in which the composition is not uniform throughout the mixture.
- A phase is a separate layer in a heterogeneous mixture.
Review
Use the link below to answer the following questions:
- Define a heterogeneous mixture.
- Why is vegetable soup a heterogeneous mixture?
- How many phases are in a heterogeneous mixture?
glass (clear versus stained) – clear glass usually looks homogeneous, stained glass could beeither, but some stained glass has bubbles in the glass so would be heterogeneous
4.Classify the following as a pure substance or a mixture. Explain your reasoning.
Get answer to your question and much more
5.Give an example of a homogeneous pure substance, a homogeneous mixture, a heterogeneouspure substance, and a heterogeneous mixture.
Get answer to your question and much more
Table of Contents
[hide][show]
- Definition
- Properties
- Homogeneous Compound
- Homogeneous Vs. Heterogeneous Mixture
- Examples
- Quiz
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:
- Homogeneous mixtures that are thoroughly mixed down to the level of molecules are called solutions.
- 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.
- Homogeneous mixtures cannot be expressed as chemical formulas.
- To describe any homogeneous mixture accurately, you need to name the components and tell their proportion or ratio within the mixture.
- 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 (H2O). 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. Good thing, too, otherwise you might pass out.
Homogeneous Vs. Heterogeneous Mixture
In chemistry, we can have two types of mixtures: homogeneous mixtures and heterogeneous mixtures:
- Homogeneous mixture: Blended so thoroughly, it looks like one substance – Uniform composition.
- Heterogeneous mixture: 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 the 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:
- What is the definition of a homogeneous mixture?
- Is a cup of coffee a homogeneous mixture?
- What does a homogeneous mixture look like?
- Is a solution a homogeneous mixture?
- Of the choices below, which are homogeneous mixtures?
- A bag of trail mix
- Air
- Italian salad dressing (oil, spices, and vinegar)
- A chocolate milkshake
- Seawater
- A steel bridge
Don't get mixed up! Do the work first, then check your answers below.
- The definition of a homogeneous mixture is one that is mixed so thoroughly that you cannot see the individual components or parts.
- Brewed coffee is a homogeneous mixture.
- 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.
- Yes, a solution is a homogeneous mixture. An example of a homogeneous solution is a soft drink.
- Of the choices below, all are homogeneous mixtures except for a., trail mix, and c., Italian dressing.
- A bag of trail mix
- Air
- Italian salad dressing (oil, spices, and vinegar)
- A chocolate milkshake
- Seawater
- A steel bridge