1. Chemistry Conversions
Dimensional Analysis and Atoms, Elements, Compounds

2. Exponential Multiplier
SI Prefixes
Prefix
Abbreviation
Exponential Multiplier
Meaning
Example using length
Kilo- k
103
1000
1 kilometer (km) = 1000 m
Hecto- h
102
100
1 hectometer (hm) = 100 m
Deka- da
101 10
1 dekameter (dam) = 10 m 1
1 meter (m)
Deci- d
10-1
1/10
1 decimeter (dm) = 0.1 m
Centi- c
10-2
1/100
1 centimeter (cm) = 0.01 m
Milli- m
10-3
1/1000
1 millimeter (mm) = m

3. Converting From One Unit to Another
We will convert A LOT!
Uses a technique called Factor Label Method
Cancels out units and does the math for you!!

4. Factor-Label Method for Conversions
Mathematics used Numbers, rather than Quantities
Chemistry uses these same Numbers along with the value’s Units
A Number is useless without its unit
Units give the Number an actual meaning

5. 1 foot / 12 inches or 12 inches / 1 foot,
Conversion Factors
A conversion Factor is needed to go from one unit to another
You must first know how much of one thing is of another before making any conversions
We all know 1 foot is made up of 12 inches
SO…
The conversion factor needed to go from feet to inches or from inches to feet is
1 foot / 12 inches or 12 inches / 1 foot,
Respectively.

6. Let’s try using 1 pound = 0.454 Kilograms
Conversion Factors
1 mile = 1.61 Kilometers
1 inch = 2.54 centimeters
1 gallon = 3.71 Liters
Let’s try using 1 pound = Kilograms

7. Conversions 1 pound = 0.454 Kg 157 lb 0.454 kg 1 lb
The “Heart” of the problem is where the conversion actually takes place. This is where your conversion factor does its work.

8. Conversions 1 pound = 0.454 Kg 157 lb 0.454 kg 1 lb
( 157 * ) / 1 = 71
= 71 kg
So yes, with the proper units 157 lb does equal 71 kg, but without units the values are not the same, as we do not know the correct representation numbers.

9. Units
Units are everything. They give any value an actual meaning and interpretation.
Always carry your units through, rewriting them until you reach a final value, or you will be lost.

10. English System (American System)
Conversions Factors:
1 foot = 12 inches
1 yard = 3 feet
1 mile = 5,280 feet = 1,760 yards
1 gallon = 16 cups = 4 quarts = 8 pints
1 pound = 16 ounces

11. Converting with English Units
Question:
Convert yards to inches:
Conversion Factors:
1 yard = 3 feet
1 foot = 12 inches

12. Converting with Metric Units
Convert yards to inches:
15.41 yd
Conversion Factors:
1 yard = 3 feet
1 foot = 12 inches

13. Converting with Metric Units
Convert yards to inches:
15.41 yd
3 ft
1 yd
Conversion Factors:
1 yard = 3 feet
1 foot = 12 inches

14. Converting with Metric Units
Convert yards to inches:
15.41 yd
3 ft
12 in.
1 yd
1 ft
Conversion Factors:
1 yard = 3 feet
1 foot = 12 inches

15. Converting with Metric Units
Convert yards to inches:
15.41 yd
3 ft
12 in.
1 yd
1 ft
= (15.4 * 3 * 12) / 1
15.41 yards = inches

16. Metric System Common Metric Prefixes: Kilometer Hectometer Dekameter
Abbreviation
Value (Base Unit)
Kilometer km
1000
Hectometer hm
100
Dekameter
dam 10
Base Unit (meter)
meter 1
Centimeter cm
0.01
Millimeter mm
0.001
Micrometer µm

17. Converting with Metric Units
Question:
Convert km to centimeters:
Conversion Factors:
1 Kilometer = 1000 meters
1 meter = 100 centimeters
Prefix
Abbreviation
Value (Base Unit)
Kilometer km
1000
Hectometer hm
100
Dekameter
dam 10
Base Unit (meter)
meter 1
Centimeter cm
0.01
Millimeter mm
0.001
Micrometer µm

18. Converting with Metric Units
Covert km to centimeters:
0.248 km
Conversion Factors:
1 Kilometer = 1000 meters
1 meter = 100 centimeters

19. Converting with Metric Units
Covert km to centimeters:
0.248 km
1000 m
1 km
Conversion Factors:
1 Kilometer = 1000 meters
1 meter = 100 centimeters

20. Converting with Metric Units
Convert km to centimeters:
0.248 km
1000 m
100 cm
1 km 1m
Conversion Factors:
1 Kilometer = 1000 meters
1 meter = 100 centimeters

21. Converting with Metric Units
Convert km to centimeters:
0.248 km
1000 m
100 cm
1 km 1m
= (0.248 * 1000 * 100) / 1
= 24,800 centimeters
Much Easier!

22. Calculations: Metric Vs. American System?
Prefix
Abbreviation
Value (Base Unit)
Kilometer km
1000
Hectometer hm
100
Dekameter
dam 10
Base Unit (meter)
meter 1
Centimeter cm
0.01
Millimeter mm
0.001
Micrometer µm
Just count the zeros and move the decimal spot to the left or the right.