Summer Research Program for Secondary School Science Teachers/Partners in Science Program
Anthony Mauro
Ft. Hamilton H.S., Brooklyn, NY
Introduction to AP Chemistry
Developing cooperative team skills
OBJECTIVES:
1. Students will be able to define key words in a definition of Chemistry.
Students will be able to work in teams to relate this definition to a particular substance and reaction.
INTRODUCTION/MOTIVATION:
Display a butane lighter. Identify the substance in the lighter as butane, a natural gas. Have a student demonstrate the procedure for lighting the burner.
DEVELOPMENT:
Give the following definition of Chemistry:
Chemistry is the branch of science that studies the composition, structure, and properties of matter, the changes that matter undergoes, and the energy that accompanies these changes.
Working in cooperative teams of 3-4, have students write definitions for the key words in the above description of chemistry. Discuss the key words and their definitions. [9-12 Content Standard B- Physical science]
Using a review book and a regents reference table, have teams relate the definition to butane and its burning reaction. Encourage students to make a written list of as many things as possible for each key word based on what they learned in Regents Chemistry. [Teaching Standard D- Make accessible science materials]
Example:
Composition of butane: Carbon and Hydrogen
Empirical and molecular formulas
Alkane (General formula)
Structure of butane: Bonding (Saturated or Unsaturated)
Structural formulas (Isomers) [Content Standard Unifying Concepts- Organization]
Properties of Butane: Natural gas in liquid form (Why?)
Density, Boiling point, Melting point [9-12 Content Standard B- Structure and properties of matter]
Changes (Reactions): Word equation of the burning reaction
Balanced equation of the burning reaction [9-12 Content Standard B- Chemical reactions]
Energy: Forms of energy; potential vs kinetic
Activation Energy
Endothermic/Exothermic [9-12 Content Standard B- Interactions of matter and energy]
H and G (Reference Table)
Lesson Plan 2
OBJECTIVES
Students will be able to determine the concentration of an unknown sample using a graph of absorbance vs concentration.
Students will derive an equation that relates absorbance and concentration. [9-12 Content Standard A- Formulate explanations using evidence]
INTRODUCTION/MOTIVATION:
Display a spectrophotometer. Explain that the concentration of solutions can be determined using this instrument. Show two different concentrations of cobalt chloride (lighter and darker colored solutions). Put samples in separate cuvettes and put each sample into the spectrophotometer. Have students read the absorbance scale and draw conclusions concerning absorbance and concentration. [Teaching Standard D- Make accessible science tools]
DEVELOPMENT:
1)Provide students with the following data table:
Samples Concentration of Cobalt Chloride Absorbance
1 .20 M .15
2 .35 M .26
3 .50 M .38
4 .65 M .49
5 .80 M .60
Unknown A _____ .20
Unknown B _____ .56
2) Working in groups of 3-4, have students write possible methods for determining the concentration of the unknowns from the data in the table. Discuss possible methods. [Content Standard Unifying Concepts- Change, constancy, and measurement]
Distribute graph paper. Have groups produce graphs and determine concentrations.
Have groups derive a formula from the graphs.
Absorbance = k x Concentration ( where k =slope)
5) Discuss Beer’s Law.