Lecture

1.1 Chemistry
1. Chemistry is the study of the composition of substances and the changes they undergo.

2. Applied chemistry uses scientific knowledge in affecting society. May be positive or negative.

3. Pure chemistry (pure science) accumulates knowledge for its own sake.

4. Five major divisions:

• Organic chemistry-carbon
• Inorganic chemistry-substances without carbon
• Analytical chemistry-concerned with composition of substances.
• Physical chemistry-concerned with theories and experiments describing the behavior of chemicals.
• Biochemistry-chemistry of living organisms.

• Cubit: Elbow to tip of middle finger
• Span: Tip of thumb to tip of little finger, hand spread
• Palm: Breadth of four fingers
• Digit: breadth of finger
• Mile: Romans - 1000 paces.
• Inch: Breadth of thumb
  

• Foot: Length of man's foot
• Yard: King Henry I of England - Distance of tip of his nose to end of thumb.
• Stone: 14 pounds, still used in England today.

1. The scientific method is an approach to the solution of scientific problems.

• Observation
• Hypothesis
• Experiment
• Revise hypothesis or repeat experiment. Test hypothesis

3. Theory is a thoroughly tested explanation of why experiments give certain results. Can never be completely proven.

4. Scientific law is a concise statement that summarizes the results of a broad spectrum of observations and experiments. Laws describe natural phenomenon, but don't explain them. (Look to theory).

1.3 Properties of Matter

1. Matter is anything that takes up space and has mass.

2. Mass is amount of matter in an object.

3. Substance is particular kind of matter that has a uniform and definite composition.

4. Physical property is a quality or condition of a substance that can be observed or measured without changing the substance's composition.

1.4 States of Matter

1. Solid is matter with definite mass, volume, and shape. Is incompressible.

2. Liquid is matter with definite mass, volume, and not shape. Almost incompressible, but expand and flow to container.

3. Gas is matter with definite mass, not volume, shape. Is compressible takes shape and volume of container. Vapor is matter in gaseous state that is liquid at room temperature.

1.5 Physical Changes

1. Physical change alters a substance without changing its composition.

1.6 Mixtures

1. Mixtures consist of a physical blend of two or more substances.

2. Variable composition.

3. Heterogeneous mixture is not uniform in composition.

4. Homogeneous mixture has a completely uniform composition.

5. Homogeneous mixtures are solutions.

6. Solutions may be combinations of all 3 states of matter. See table 1.5, page 12.

7. Any part of a system with uniform composition and properties is called a phase.

8. Since mixtures are physical combinations, they may be separated by physical methods. Eg, distillation, filtration, etc.

1.7 Elements and Compounds.

1. Elements are the simplest forms of matter that can exist under normal laboratory conditions. Cannot be separated into simpler substances.

2. Two or more elements may combine to form compounds.Compounds are substances that can be separated into simpler substances only by chemical reaction.

1.8 Chemical Symbols

1. Each element is represented by a chemical symbol.

1.9 Chemical Reactions.

1. In a chemical reaction one or more substances change into new substances. Chemical Change.

2. In a chemical reaction, the starting substances are called reactants and the new substances are the products.

3. The ability of a substance to undergo chemical reactions and to form new substances constitutes its chemical properties.

1.10 Conservation of Mass

1. The law of conservation of mass states that in any physical or chemical reaction, mass is neither created nor destroyed; it is conserved.