© Copyright Pearson Prentice Hall Mixtures Slide 1 of 21 > Classifying Mixtures What are mixtures and how can we classify them? 2.2

Slide 2 of 21 © Copyright Pearson Prentice Hall > Mixtures Classifying Mixtures A mixture is a physical blend of two or more components. A salad bar provides a range of items. Customers choose how much of each item to use in their salads. Each salad has a different composition. 2.2

© Copyright Pearson Prentice Hall > Slide 3 of 21 Mixtures Classifying Mixtures Based on the distribution of their components, mixtures can be classified as heterogeneous mixtures or as homogeneous mixtures. 2.2

Slide 4 of 21 © Copyright Pearson Prentice Hall > MixturesClassifying Mixtures Heterogeneous Mixtures A mixture in which the composition is not uniform throughout is a heterogeneous mixture. 2.2

Slide 5 of 21 © Copyright Pearson Prentice Hall > MixturesClassifying Mixtures Homogeneous Mixtures A mixture in which the composition is uniform throughout is a homogeneous mixture. Another name for a homogeneous mixture is a solution. 2.2

© Copyright Pearson Prentice Hall Slide 6 of 21

© Copyright Pearson Prentice Hall Slide 7 of 21

© Copyright Pearson Prentice Hall Slide 8 of 21 Mixtures, compounds, elements MIXTURES Not in a fixed ratio Separated physically- use physical properties Individual components retain their properties COMPOUNDS In a fixed ratio (formula) Separated chemically Different properties than elements that compose it. (ex. NaCl)

© Copyright Pearson Prentice Hall Slide 9 of Separating Mixtures How can mixtures be separated? Differences in physical properties can be used to separate mixtures

Slide 10 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Filtration The process that separates a solid from the liquid in a heterogeneous mixture is called filtration. A colander is used to separate pasta from the water in which it was cooked. This process is a type of filtration. 2.2

Slide 11 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Distillation During a distillation, a liquid is boiled to produce a vapor that is then condensed into a liquid. 2.2

Slide 12 of 21 © Copyright Pearson Prentice Hall > Mixtures Distinguishing Elements and Compounds An element is the simplest form of matter that has a unique set of properties. A compound is a substance that contains two or more elements chemically combined in a fixed proportion. Ex. Sugar C 6 H 12 O 6 2.3

Slide 13 of 21 © Copyright Pearson Prentice Hall > Mixtures Distinguishing Elements and Compounds Breaking Down Compounds A chemical change is a change that produces matter with a different composition than the original matter. When table sugar is heated, it goes through a series of chemical changes. C 6 H 12 O 6 → 6 C + 6 H 2 O 2.3

Slide 14 of 21 © Copyright Pearson Prentice Hall > Mixtures Distinguishing Elements and Compounds Properties of Compounds In general, the properties of compounds are quite different from those of their component elements. When the elements sodium and chlorine combine chemically to form sodium chloride, there is a change in composition and a change in properties. Compounds can only be separated by chemical means 2.3

Slide 15 of 21 © Copyright Pearson Prentice Hall > Mixtures Distinguishing Substances and Mixtures This flowchart summarizes the process for classifying matter. 2.3

Slide 16 of 21 © Copyright Pearson Prentice Hall > Mixtures Symbols and Formulas Chemists use chemical symbols to represent elements. One or two letters, first letter always capitalized 2.3

Slide 17 of 21 © Copyright Pearson Prentice Hall > Mixtures COMPOUNDS Compounds are composed of 2 or more elements chemically bonded together. They are represented by chemical formulas. You know there are 3 elements because they are capitalized.