1. Unit Conversion: The Factor Label Method

2. You can convert from one unit to another using a conversion factor A conversion factor is an expression for the relationship between units – Ex: converting 90 minutes to hours

3. Step 1 Show what you are given on the left and what units you want on the right 90 min = ? Hrs

4. Step 2 Insert the required conversion factors to change between units Only one conversion factor is needed – The conversion factor is shown as the fraction 1hr/60min. – The minutes unit is placed on the bottom so it will cancel out with the minutes unit on the top – 90min x 1hr= ? hrs 60 min

5. Step 3 Cancel units and solve the math 90 min x 1=1.5 hrs 60 min

6. Example: A student determines that the density of a certain material is 4.46 g/cm 3. What would be the density if this material in g/L? Solve this problem in your notebook

7. ANSWER:

8. To solve this problem you have to know how many cm 3 is in 1 L (liter). 1L= 1,000 cm 3 Step1: Show what you are given on left, and the units you want on the right 4.46g/cm3 = ? g/ L Step 2: Insert the required conversion factors to change between units & cancel units were you can 4.46g/cm3 x 1 L = 1,000 cm3

9. Step 3 Cancel units were you can and solve the math 4.46g/L = 0.0046 g/L 1000