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Chapter 3 Problem Solving in Chemistry

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					Chapter 3: Problem Solving in
         Chemistry

       ADVANCED CHEMISTRY
           MRS. PIERCE
          3.2 Techniques of Problem Solving

 Steps to follow when solving problems….
   Identify the Unknown
        What should units be?
    Identify what is Known or Given
        Any extra/unnecessary information?
    Plan a Solution
      Look up any constants or equations (if necessary)
      Compare Units of Given and of Unknown
    Do the Calculations
        Always double-check units/work!
    Finish Up
        Final Check!
                 3.3 Conversion Factors

 Conversion Factors (equivalent measurements)
 are commonly used in Chemistry to solve problems!
    Examples…
      $1.00 = 4 Quarters = 10 Dimes = 20 Nickels = 100 Pennies
      1 m = 10 dm = 100 cm = 1,000 mm
      1 kg = 1,000 g
      1 g = 10 dg = 100 cg = 1,000 mg
      1 L = 1,000 mL
                 3.4 Dimensional Analysis

 In dimensional analysis you use the units
 (dimensions) that are part of measurements to help
 solve (analyze) a problem.
    Follow the in-text example on pages 65-67!
    Add’l Examples…
        Mrs. Pierce is preparing a laboratory experiment. There are 6
         laboratory groups that will be completing the experiment. The
         experiment calls for 10.0 g of sodium chloride, NaCl. Mrs. Pierce
         has located 123.0 g of NaCl in the stock room. Does she have
         enough for all of the laboratory groups?
           3.5 Converting Between Units

 When completing a chemistry experiment/problem,
 one will often have to express measurements in a
 unit that is different from the one given in the
 problem!
    See Examples 4 & 5 in the book (page 69)
                3.6 Multistep Problems

 Many problems in Chemistry are more easily solved
 if broken down into simpler steps.
    More than one conversion factor is often necessary to solve a
     problem!
    See Examples 6 & 7 (pages 72 & 73)
          3.7 Converting Complex Units

 When a problem involves units containing two types
 of measurements (densities, speeds, etc.), it is
 critical to keep track of units that have been
 cancelled/converted!
    Always double check units when solving problems!!!
    See Example 8 (page 75)

				
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