Honors Chemistry Chapters 1 2

1
Honors ChemistryChapters 1 2

• Chemistry- Matter and change

2
Science vs. Chemistry

• Science- "knowledge attained through study or
  practice (Websters)
• Translation Systematic approach to determine the
  nature of the universe
• Translation Using the scientific method to
  investigate the world

• Chemistry- the study of the composition and
  changes undergone by materials
• Translation Using the scientific method to
  figure out what stuff is and what it can do

3
Five Branches of Chemistry

• Organic
• Inorganic
• Analytical-composition of substances.
• Physical-behavior of chemical substances
• Biochemistry

4
Chemistry Can Be

• Pure
• For the advancement of knowledge about our world

• Applied
• For a specific issue that faces society
• Pharmaceuticals, etc.

5
Scientific Method

• Question
• Hypothesis
• Experiment
• Results
• Conclusion
• Peer review
• Maybe,
• much, much later
• Theory/Law

6
Important Distinctions

• Hypothesis
• After RESEARCH
• States a specific prediction based on past
  experimental results or research
• Usually in the IF, THEN format

• Experiment
• Designed to INVESTIGATE THE HYPOTHESIS

7
Important Distinctions

• Results
• Compile and LOOK FOR PATTERNS in experimental
  results
• DOES NOT EXPLAIN WHY

• Conclusion
• Explains WHY for the results
• Addresses whether or not the results SUPPORT or
  REFUTE the HYPOTHESIS
• Errors and future research are offered here

8
Important Distinctions

• BOTH
• After EXTENSIVE, DIVERSE, AND RELIABLE data
  exists
• Require many years of research and support from
  many fields

• Law
• Tells what

• Theory
• Explains why

• THIS IS THE BEST SCIENCE CAN DO!!!
• SCIENCE DOES NOT PROVE

9
Important Distinctions Continued

• Qualitative- sensory observations (EX brown)
• Quantitative- numerical measurements (EX 5 lbs)
• Observation- objective explanation of phenomena
• Inference- subjective explanation of phenomena

10
Classification of Matter

• Matter CAN change state
• Three basic states of matter

SOLID LIQUID GAS
Definite Shape
Definite Volume
Particle Spacing
11
More Important Distinctions

• Material- specific type of matter
• Matter- has mass and takes up space (has property
  of inertia)
• Mass- amount of stuff in an object
• Weight- force of gravity of mass
• Mixture- composed of 2 or more substances
  physically combined
• Heterogeneous- composition varies
• Homogeneous (solution) - uniform composition
• Substance- purely 1 type of matter (elements and
  compounds)
• KNOW YOUR ELEMENTS

12
Separating Mixtures

• ALL MIXTURES CAN BE SEPERATED PHYSICALLY
• Filtration- used to separate a mixture with
  widely varying particle size
• EX rocks and water
• Distillation- used to separate a liquid mixture
• EX alcohol and water
• Crystallization- used to separate an aqueous
  mixture
• EX salt water
• Chromatography- separates a mixture based on
  polarity (affinity for stationary/mobile phase)

13
Distillation
14
Changes to Matter

• Physical change- occurs without altering makeup
• Chemical change- occurs through alteration of
  substance

15
Chemical Reactions

• Must involve at least one material changing into
  a new material
• and
• Must obey the Law of Conservation of Mass
• Mass is neither created nor destroyed in chemical
  reaction