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Moles, Units, and Conversion Factors

Moles, Units, and Conversion Factors

Moles,Moles, Units,Units, andand ConversionConversion FactorsFactors

PresentedPresented by:by: CenterCenter forfor TeachingTeaching andand LearningLearning andand DanielDaniel FoxFox WhyWhy dodo wewe measure?measure? • standardize •compare • quantify ExamplesExamples ofof measurementmeasurement • Speed- 100 MPH • Cooking- 4 cups flour • Building- 8 walls • Weight- lbs, g, kg, etc. • Money- dollars, euros, yen • - (??!!) EnglishEnglish MeasurementMeasurement SystemSystem

• : • 12 (in) = 1 foot (ft) 3 feet = 1 (yd) 5280 feet = 1 (mi) • Capacity: • 3 (tsp) = 1 (tbsp) 16 tbsp = 1 (c) 8 (oz) = 1 c 2 c = 1 (pt) 2 pt = 1 (qt) 4 qt = 1 (gal) • Weight: • 16 ounces (oz) = 1 (lb) 2000 lb = 1

http://regentsprep.org/Regents/math/meteng/LesEng.htm MetricMetric SystemSystem ofof MeasurementMeasurement • Length - meters • - Liters • - • - EnglishEnglish--MetricMetric ConversionsConversions

http://www.its.dot.gov/transit_dev/BusSignage/images/conversionFactors.gif ScientificScientific NotationNotation

1,540,000,000,000 = 1.54 X 1012 0.00000000000154 = 1.54 X 10-12 Write these in scientific notation: 65,800,000 = 6.58 X 107

0.125 = 1.25 X 10-1 MetricMetric toto metricmetric conversionsconversions

9 10 106 103 100 10-1 10-2 10-3 10-6 10-9 Giga-(G) Mega-(M) kilo-(k) m deci-(d) centi-(c) milli-(m) micro-(µ) nano-(n) g Larger L Smaller Measurements s TheThe molmol • Avagadro’s Number

6.02 X 1023= 1 mol

• Used as a ratio to compare different atomic elements MetricMetric toto MolesMoles • Write this:

mass

mols MolesMoles toto ## AtomsAtoms • Write this:

#Atoms

Avagadro’s mols Number 6.02 X 1023 molsmols ExampleExample • How many mols of are in 5g of carbon? 5g carbon = 0.417 mols of carbon 12 g/mol • How many moles of are in 12

g of CO2?

• 12g CO2 X 2 atoms O =~0.55mols

44 g/mol 1 CO2 #Atoms#Atoms exampleexample • How many atoms of Cl are in 0.43 mols of NaCl? 0.43mols (6.02 X 1023) = 2.59 X1023atoms • How many atoms of Na are in 3g of NaCl? 3g NaCl (6.02 X 1023) = 3.11 X 1023atoms 58 g/mol MolarityMolarity (M)(M) • Represents of moles in a solution • Measured in moles/Liter

•Ex: • A 1 Molar solution of NaCl: 1 mol NaCl 1 L solution ApplicationsApplications • Moles and molarity are used to: – Determine amount of substance needed – Calculate limiting reactants – Compare different elements and compounds on a standard ApplicationApplication questionquestion #1#1 • How many grams of NaCl are required to make 500mL of a 2.0M solution? 2.0 moles/liter (0.5L)= 1mol NaCl

1mol NaCl(58 g/mol) = 58 g NaCl ApplicationApplication questionquestion #2#2

• What is the molarity of 4g CaCl2 dissolved into 800mL of solution?

4g CaCl2 = .036mols CaCl2 110 g/mol

.036mols= 0.045M solution 0.8L ApplicationApplication questionquestion #3#3 • How many mols of HCl are required to make 600mL of a 1.5M solution?

1.5mol/liter (0.6L) = 0.9 mols Happy Halloween!

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