## DIMENSIONAL ANALYSIS (also known as Factor-Label Method)
## Read problem ## Make a unit plan from the initial unit to the desired unit ## Change initial unit to desired unit ## Do math on calculator
## Conversions ## If you know ONE conversion for each type of measurement, you can convert anything! ## You must memorize and be able to use the metric conversions:
**Conversion Factors** ## Fractions in which the numerator and denominator are EQUAL quantities expressed in different units ## ## Example: 1 ft = 12 in. ## Factors: __ 1 ft. __ and __ 12 in __ ## 12 in 1 ft. ## ## Example: 1 g = 102 cg. ## Factors: __ 1 g. __ and __ 102 cg __ ## 102 cg 1 g
##
## How many minutes are in 2.5 hours? ** ***Conversion factor*
* *
* ***2.5 hr x **__ 60 min__ = 150 min
** 1 hr**
** *** *
## Sample Problem ## You have $7.25 in your pocket in quarters. How many quarters do you have? **7.25 dollars** **4 quarters**
## **1 dollar**
## You have 200 L of gasoline in your car. How many milliliters do you have? **200 liters** **103 milliliters**
## **1 liter**
**Learning Check** ## ## 2.22 cg = _______g ## 1.7 x 106 ng = ___________ g ## .288 g = __________mg ## 1.5 KL = ___________L
##
## You are in Paris and want some peaches for lunch. The sign in the fruit stand indicates that peaches are 11.5 francs per kilogram. Given that there are approximately 5 francs to the dollar, calculate what a pound of peaches will cost in dollars.
## Practice Problems ## Mrs. Borden has 3 classes of Chemistry. Each class has 25 students in it and they are each required to pay $15.00 for their lab fee. How much money will she have at the end of the semester if everyone pays their fee? ## Students in chemistry are required to write 10 lab reports per year. Each lab report has 6 sections each. Mrs. Borden requires that each section consists of a paragraph with no less than 7 sentences. How many paragraphs will each student write in 1 year time?
## Complex Units
## YOU TRY IT ## The density of gold is 19.3 g/mL. What is gold’s density in decigrams per liter?
## NEW UNITS ## These are units you have never used but you must know for the rest of the year. ## 1 mole of any element or compound = ## 1 mole of any element or compound = ## 6.02 x 1023 representative particles
## CONVERSION FACTORS -
## How to calculate mass, using the periodic table: Na = 23.0 g and Cl = 35.5 g ## 23.0 ## +__ 35.5__ therefore 1 mole of NaCl = 58.5 g ## 58.5 g
## Practice pROBLEM ## You are given 3.5 moles of NaCl, how many grams of NaCl do you have?
## CONVERSION FACTORS ## therefore 1 mole of NaCl = 6.02 x 1023 Particles or __1 mole of NaCl__ ## 6.20 x 1023 particles
## Practice pROBLEM ## You are given 3.5 moles of NaCl, how many particles of NaCl do you have?
## Multi-Step Problems ## You are given 4.55 x 1025 particles of oxygen, how many grams of oxygen do you have?
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