Physical Properties of Matter

1. Physical Properties of Matter S. Ramsay 2004-5

2. Introduction Chemistry is the study of: • The composition, structure, and properties of matter. • The changes which matter undergoes. • The energy that accompany changes in matter. S. Ramsay 2004-5

3. Some Branches of Chemistry • Physical chemistry • Inorganic chemistry • Organic chemistry • Analytical chemistry • Biochemistry • Polymer chemistry • Food chemistry • Applied chemistry S. Ramsay 2004-5

4. Physical Properties Physical properties are those characteristics of a substance that can be observed with the senses. Examples: Shape Color Texture Texture Melting point Boiling point Density S. Ramsay 2004-5

5. Physical Properties Instruments can be used to help the senses observe certain physical properties. Examples: X-ray diffraction – observe crystal structure and texture. Electron microscope – make observation on the molecular level. Electron Microscope X-ray Diffractometer S. Ramsay 2004-5

6. Types of Matter • Substance – has parts with the same properties and composition. • Element - made of all the same atoms, and cannot be broken down by chemical change. • Compound - 2 or more elements chemically combined in a fixed ratio, and can be broken down by a chemical change. Binary compounds consist of only two elements. • Mixtures – two or more substances with different physical and chemical properties. The composition of a mixture can vary, and it can be separated by physical change. • Homogeneous mixture (solution, mixture of gases) • Heterogeneous mixture S. Ramsay 2004-5

7. S. Ramsay 2004-5

8. Separating Mixtures Some methods used to separate mixtures: • Distillation – based on boiling point. • Chromatography – based on size of molecules. • Filtration – used to separate 2 phases. S. Ramsay 2004-5

9. S. Ramsay 2004-5

10. Gel Permeation Chromatography(Technique for use on polymers) Polystyrene Toluene (marker) Sample peaks { S. Ramsay 2004-5

11. The 3 Phases of Matter • Solid have definite shape and volume. • Liquid have definite volume and indefinite shape. • Gas have indefinite volume and indefinite shape. • By absorbing or releasing energy matter can change from one phase to another. S. Ramsay 2004-5

12. Liquids • Liquids have definite volume and take the shape of their container. • A liquid will boil when its vapor pressure is equal to atmospheric pressure. Boiling point is the temperature at which the liquid’s vapor pressure = atmospheric pressure. • Heat of vaporization = heat required to vaporize unit mass of a liquid at constant temperature. S. Ramsay 2004-5

13. Barometric Pressure S. Ramsay 2004-5

14. Vapor Pressure S. Ramsay 2004-5

15. Solids • Solids have definite volume and definite shape. • All true solids have a crystal structure. • Heat of fusion = heat required to melt unit mass of a solid at constant temperature. S. Ramsay 2004-5

16. Crystal Lattices S. Ramsay 2004-5

17. Types of Cubic Structures S. Ramsay 2004-5

18. Metallic Crystals S. Ramsay 2004-5

19. S. Ramsay 2004-5