Mixtures Chemistry2.2

Mixtures Panning is one way to separate gold from a mixture of gold and materials such as sand or gravel. In this section you will learn how to separate mixtures.

Classifying Mixtures A mixture is a physical blend of two or more components. Salads are one type of mixture. You can choose the amount of each item you select from a salad bar. So your salad is unlikely to have the same composition as other salads containing the same items.

Types of Mixtures Heterogeneous Mixture Homogeneous Mixture A mixture in which the composition is not uniform throughout is a heterogeneous mixture. In other words, you can see the components- either with or without a microscope Homogeneous Mixture A mixture in which the composition is uniform throughout is a homogeneous mixture. In other words, you cannot see the components, even with a microscope Another name for a homogeneous mixture is a solution.

2.2 Classifying Mixtures Phase -any part of a sample with uniform composition and properties. A homogenous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases.

2.2 Classifying Mixtures When oil and vinegar are mixed they form layers, or phases. The oil phase floats on the water phase. Olive oil and vinegar are homogeneous mixtures. The substances in these mixtures are evenly distributed. When olive oil is mixed with vinegar, they form a heterogeneous mixture with two distinct phases.

Separating Mixtures Separating Mixtures How can mixtures be separated? Remember that mixtures are physical combinations, so physical changes can be made to separate the mixtures Differences in physical properties can be used to separate mixtures.

Separating Mixtures Filtration The process that separates a solid from the liquid in a heterogeneous mixture is called filtration. Filtration is used to separate cooked pasta from the water in which it was cooked In chemistry, we’ll often use filter paper to separate a solid and a liquid. A colander is used to separate pasta from the water in which it was cooked. This process is a type of filtration.

Separating Mixtures Distillation During a distillation, a liquid is boiled to produce a vapor that is then condensed into a liquid. This method can separate 2 liquids that have different boiling points A distillation can be used to remove impurities from water. As liquid water changes into water vapor, substances dissolved in the water are left behind in the distillation flask. Inferring What can you infer about the boiling points of substances dissolved in the impure water?