1. Section 1: Chemical Calculations
Unit 6: Stoichiometry
Section 1: Chemical Calculations

2. How many jumps does it take?
Ladder Method 1 2 3
KILO 1000 Units
Meters Liters Grams
CENTI 0.01 Unit
MILLI Unit
How do you use the “ladder” method?
1st – Determine your starting point. 2nd – Count the “jumps” to your ending point. 3rd – Move the decimal the SAME number of jumps in the SAME direction.
Ex: 4 km = _________ m
Starting Point
Ending Point
How many jumps does it take? 4. 1
__. 2
__. 3
__.
= 4000 m

3. Metric Calculations Common Measurement Conversion Factors Length:
1 mile (mi) = 5,280 feet (ft)
1 kilometer (km) = 1,000 meters (m)
1 centimeter (cm) = 10 millimeters (mm)
1 meter (m) = inches (in)
1 inch (in) = 2.54 centimeters (cm)
Volume:
1 gallon (gal) = 4 quarts (qt)
1 quart (qt) = 0.95 liters (l)
1 quart (qt) = 32 ounces (oz)
Mass:
1 kilogram (kg) = 2.2 pounds (lb)
454 grams (g) = 1 pound (lb)
1 pound (lb) = 16 ounces (oz)

4. Dimensional Analysis Method of calculation in conversions
- Example 1: How many seconds are there in 2.3 days?
Unit you want next goes on top
Unit you want to cancel out goes on bottom

5. Dimensional Analysis
Example 2: Calculate the number of milliliters in 10.2 gallons of gasoline.

6. Conversion Factors Problems are given in this format:
A x B x D = F
C E
To solve you enter it into the calculator as follows:
A x B ÷ C x D ÷ E = F
General idea: every numerator value is multiplied and every denominator value is divided.

7. Scientific vs. Standard Notation
Move decimal until number is between 1 and 10. Number of times moved is the exponent:
Moved to the left: Positive Exponent
Moved to the right: Negative Exponent
Scientific Notation:
54 = 5.4 x 101
70,789 = x 104
= 8.98 x 10-2
Standard Notation:
2.44 x 105 = 244,000
7.053 x 10-2 =
6.8 x 101 = 68

8. Calculator Practice
Ex: (5.5x105)(2.1x104) =
7.1x103