CHAPTER 4 OUTLINE
PROBLEM SOLVING IN CHEMISTRY

I. What Do I Do Now?
     A. Skills Used in Solving Problems
          1. Do problem solving everyday
          2. Develop a plan
          3. Utilize different techniques dependent upon the problem
     B. A Three-step Problem-Solving Approach
          1. Analyze
               a. Identify the known info and the unknown info
               b. Develop a plan
          2. Calculate
               a. Substitutions, math, formulas, etc.
          3. Evaluate
               a. Does the answer make sense?
               b. Correct units?
               c. Correct # of sig. figs.?
II. Simple Conversion Problems
     A. Conversion Factors
          1. A ratio of equivalent measurements
               a. The value in numerator = the value in denominator
               b. The ratio will always equal 1
          2. Useful for changing units on a given quantity
     B. Dimensional Analysis
          1. Solving by using the units (dimensions) of measurement
                    Ex.     15000 mm = ? in.
                              Ans. 600 in.
     C. Converting Between Units
                   Ex.      20 cg = ? g
                              Ans. .2 g
III. More Complex Problems
     A. Mulitstep Problems
          1. Break complex problems down into smaller problems
                   Ex.      How many seconds are in one day
                           step 1: convert days into hours
                           step 2: convert hours into minutes
                           step 3: convert minutes into seconds
                              Ans. 86400 seconds
     B. Converting Complex Units
          1. Common answers are expressed as ratios of units
          2. Conversion same as simple conversions
          3. Only difference -- don't forget to square or cube conversion factors if necessary


Outline based upon:
     Matta, M. S., Staley, D. D., Waterman, E. L., & Wilbraham, A. C. (2000). Chemistry, Addison-Wesley. (5th ed.). Menlo Park, Ca: Prentice Hall, pp. 83-100


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