1. Chapter 3
Properties of Matter

2. What is chemstry?
The study of matter and the changes that it undergoes.

3. What is matter?
Anything that has mass and takes of space.

4. Substances
Matter with a uniform and unchanging composition is a pure substance.
Examples:
Water (pure) – H2O
Table Salt – NaCl
Tap water and sea water are not pure substances, why not?

5. Mixtures
A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.
Example
Fillings are actually a mixture of mercury and silver.
Oil and vinegar salad dressing

6. Two types of mixtures
A heterogeneous mixture does not blend smoothly throughout and the individual substances remain distinct.
Examples
Orange juice with pulp
Oil and vinegar salad dressing

7. A homogeneous mixture has a constant composition.
Examples
Amalgam fillings
Tap water
Air
Sugar water

8. Homogeneous mixtures are also called solutions
Solutions can be solids, liquids or gases or they can be a combination of any of the three.
A solid-solid solution is called an alloy.
Examples
Steel = iron and carbon
Bronze = copper and tin

9. Gas-gas solution: air in a scuba tank (N, O, Ar)
Gas-liquid solution: O2 and CO2 in sea water
Liquid-gas solution: H2O in the air we breathe
Liquid-Liquid solution: fresh water mixes with sea water
Solid-Liquid solution: salts in sea water

10. States of Matter
Solid
Liquid
Gas
Plasma

11. A solid has its own definite shape and volume.
The particles of a solid are tightly packed
It will not conform to the container in which it is placed.
It cannot be compressed into a smaller volume.

12. A liquid is a form of matter that flows, has constant volume, and takes the shape of its container.

13. A gas is a form of matter that flows, conforms to the shape of its container and fills the entire volume of its container.
Gases are easily compressed.

14. Physical Properties of Matter
A characteristic that can be observed or measured without changing the samples composition is a physical property.
Physical properties also describe pure substances because substances have a uniform and unchanging chemical composition.
Substances also have consistent and unchanging physical properties.
EXAMPLES OF PHYSICAL PROPERTIES:
Density, hardness, color, melting point, odor, boiling point, chemical formula

15. Two types of physical properties
Extensive properties – are dependent on the amount of a substance present
Examples:
Mass, length, volume
Intensive properties – independent of the amount of a substance present.
Substances can often be identified by their intensive properties.
Scent, density

16. Chemical Properties of Matter
The ability of a substance to combine with or change into one or more other substances is a chemical property.
Examples:
Iron forming rust
No change or reaction

17. Observing Properties of Matter
Properties (Chemical and physical) of a substance might change depending on the conditions under which they were observed.
It’s important to identify the specific conditions (such as temperature and pressure) under which observations are made.
Physical and chemical properties depend on these conditions.

18. Examples of varying chemical and physical properties at different conditions:
At standard temperature and pressure H20 is a liquid (physical property) and not chemically reactive (chemical property) and has a density of 1.00 g/cm3 (physical intensive property)
At temperatures greater than 100 degrees C, H20 is a gas (physical property) with a density of g/cm3 (physical intensive property) and reacts readily with many different substances (chemical property)

19. Changes in Matter Physical Changes
A change that alters a substance without changing its composition is a physical change.
Examples of physical change:
Cutting a sheet of paper breaking crystal

20. A transition of matter from one state to another state is a phase change.
Examples of phase change
Gas to a liquid
Terms such as boil, freeze, condense, vaporize or melt in chemistry typically refer to a phase change in matter.
The temperature at which a substance undergoes a phase change is an important physical property; these properties are called the melting point and boiling point.

21. Chemical Changes
A chemical change is a process that involves one or more substances changing a new substance (commonly referred to as a chemical reaction)
The new substances formed in the reaction have different chemical compositions and properties from the original substance.

22. In chemical reactions the starting substances are called reactants and the new substances formed are called products.
Terms such as decompose, explode, rust, oxidize, corrode, tarnish, ferment, burn, or rot generally refer to chemical reactions.

23. C12H22O11 + H2SO4  12C + 11H20 reactants products

24. Separating Mixtures
To really be able to understand a mixture, its components have to be separated out.
Because mixtures are physically combined, it requires a physical process to separate them out.

25. Ways to Separate Mixtures
Filtration – A technique that uses a porous barrier to separate a solid from a liquid.

26. Distillation – a separation technique that is based on differences in the boiling points of the substances involved.

27. Crystallization – a separation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance.
Example – Rock candy being made

29. Sublimation
The process during which a solid changes to vapor without melting/ without going through the liquid phase.

30. Chromatography
A technique that separates the components of a mixture based on the ability of each component to travel or be drawn across the surface of another material.

31. Elements and Compounds
Element - An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.

33. Compound - Made of two or more different elements that are combined chemically.
NaCl - table
H2O - water
H2O2 – hydrogen peroxide
Compounds are different from the elements they are made of and have different properties

34. Familiarize yourself with the chart on p. 87 in Chapter 3

35. Law of definite proportions
States that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample.

36. Percent by Mass
The ratio of the mass of each element to the total mass of the compound expressed as a percentage
Percent by mass= mass of the element/mass of the compound X 100

37. Practice Problem p.88 #19-22 Complete the problems listed above
2/22/2019
Practice Problem p.88 #19-22
Complete the problems listed above
#19 – 15.9%
#20 – 5.0%
#21 – 25% X and 75% Y
#22 – No, Compound I = 11.1% H, Compound II = 5.9% H

38. You only need to know this one in definition form!!!
2/22/2019
LAW OF MULTIPLE PROPORTIONS = when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in a ratio of small whole numbers
Ex. Water H2O and hydrogen peroxide H2O2, same relative hydrogen to each other but hydrogen peroxide has twice as much oxygen, ratio of 2:1
Mass ratio of compound I / mass ratio of compound II
You only need to know this one in definition form!!!