1. Chapter 2 Properties of Matter

2. Matter
Pure Substances
Elements
Compounds
Mixtures
Homogenous
Heterogeneous

3. Matter has three states
Solid:
Liquid
Gas

4. Energy is related to State
KINETIC ENERGY
Vibrational
Rotational
Translational

5. Energy is related to state
Potential Energy: Related to the position of the molecules wrt one another. Energy must be added to the system to stretch the molecules apart. Think of a rubber band.

6. A phase diagram is a picture of energy Changes
Where there is a phase change: energy is added as potential.
Where there is a temperature change: energy is added as kinetic.
The total change in energy is the sum of all the energy added and/or lost

7. A picture of Energy
A plot of DT vs DQ
Temperature
Energy added

8. High energy changes cause chemical change
Interacts with matter
Low energy changes cause physical change in matter
Changes in state = PE
Melting
Evaporation
Changes in temp. = KE- indicates change in motion
High energy changes cause chemical change

9. Pure substances
Matter that always has exactly the same composition is classified as a pure substance

10. Laws that Govern Pure Substances
Law of Conservation of Mass/Energy
Law of Definite Composition
Law of Multiple Proportions

11. Conservation of Mass
During a chemical reaction, the mass of the products is always equal to the mass of reactants
Law of Conservation of Mass

12. Law of definite composition
In a pure compound the elements are always combined in fixed proportions by weight
Ex: water

13. Chemical Change = Chemical Reaction

14. Law of Multiple Proportions
The principle that two elements that can form more than one compound combine in the ratio of small whole numbers

15. Law of multiple proportions

16. Types of Pure substances
Element- simplest form of matter contains only one type of atom
Compound- contains two or more elements chemically combined
- can be broken down into two or more elements using
chemical process

17. Elements And Compounds
Elements are represented by symbols
Compounds are represented by chemical formulas, groups of element symbols

18. Chemical Symbols 1st letter always upper case Each element has its own
2nd and 3rd always lower case
Represents one atom (or mole) of the element

20. Compounds
C6H12O6

21. Chemical Formula – the “recipe” for a compound.
Tells what elements are in the compound.
Tells # of atoms of each element.
Ex. H2O = 2 atoms of hydrogen and 1 atom of oxygen
Ex. NaCl C6H12O H2SO4

22. Mixtures Mixture-physical blend of two or more components 2 Types:
Heterogeneous
Homogenous (solution)

23. Mixtures
Heterogeneous – parts of the mixture are noticeably different form each other
Homogeneous- parts of the mixture are evenly distributed

24. Types of Mixtures
Homogeneous
Heterogeneous

25. Physical Properties
Physical property- any characteristic of a material that can be observed or measured without changing the composition of the substances
viscosity
Conductivity
Malleability
Hardness
Melting point
Boiling point
density

26. Physical properties : Viscosity

27. Chemical properties
Chemical property-any ability to produce a change in composition of matter
Flammability
Reactivity
Toxicity
Heat of combustion

28. Chemical properties : Reactivity
Chemical reactivity- property that describes how easy it is for a substance to chemically combine with another substance
Ex: oxygen – high reactivity
nitrogen - low reactivity

29. Chemical Changes (Rxn)
During a chemical change, the composition of matter always changes
Reactant
Product

30. Indicators of Chemical Change
Formation of precipitate
A solid that forms and
separates from a mixture
Production of a gas
Change in pH
Energy change
Color change
Light