Chapter 3: Problem Solving in
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!
3.3 Conversion Factors
Conversion Factors (equivalent measurements)
are commonly used in Chemistry to solve problems!
$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!
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
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
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
Always double check units when solving problems!!!
See Example 8 (page 75)