Factor Label Review Factor Label Review &&

Mole CalculationsMole Calculations

Factor Label MethodFactor Label Method

givenofunit

findtounitxvaluegiven

1.1. write down given valuewrite down given value

2.2. write unit of given in denominatorwrite unit of given in denominator

3.3. write unit to find in numeratorwrite unit to find in numerator

4.4. insert numerical valuesinsert numerical values

5.5. solvesolve

Factor Label ExampleFactor Label Example

How many hours are in 3.75 years?How many hours are in 3.75 years?( Known: 1 year = 365.25 days( Known: 1 year = 365.25 days 1 day = 24 hours )1 day = 24 hours )

hoursday

hoursx

year

daysxyears 5.32872

1

24

1

25.36575.3

Step 2: insert numerical values and calculateStep 2: insert numerical values and calculate

hoursday

hoursx

year

daysxyears 5.32872

1

24

1

25.36575.3

Step 1: set up problem by inserting unitsStep 1: set up problem by inserting units

Molar RelationshipsMolar Relationships

Mole as a number of particlesMole as a number of particles

Molar MassMolar Mass

Molar Volume of a GasMolar Volume of a Gas

Mole to Particle ConversionsMole to Particle Conversions

1 mole = 6.02x101 mole = 6.02x102323 molecules or atoms molecules or atoms

Problem1 : Problem1 :

How many molecules are in 1.75 moles of NHow many molecules are in 1.75 moles of N22??

224

2

223

2 .1005.11

.1002.675.1 Nmolecx

Nmole

NmolecxxNmoles

Mole to Particle Conversions #2Mole to Particle Conversions #2

1 mole = 6.02x101 mole = 6.02x102323 molecules or atoms molecules or atoms

Problem2 : Problem2 :

How many moles are in 2.59x10How many moles are in 2.59x102222 molecules of molecules of NN22??

22

232

222 0430.0

.1002.6

1.1059.2 Nmoles

Nmolecx

NmolexNmolecx

Molar MassMolar Mass

Molar MassMolar Mass = = mass of 1 mole of a substancemass of 1 mole of a substance

ElementsElements: atomic mass in units of grams: atomic mass in units of grams

Na = 23.0 gramsNa = 23.0 grams Cl = 35.5 gramsCl = 35.5 grams

CompoundsCompounds: sum of individual masses in grams: sum of individual masses in grams

NaCl = 58.5 gramsNaCl = 58.5 grams CaClCaCl22 = 111.1 grams = 111.1 grams

Mole to Mass ConversionsMole to Mass Conversions

1 mole = X grams of element/substance1 mole = X grams of element/substance 1 mole NaCl = 58.5 g1 mole NaCl = 58.5 g

Problem 1:Problem 1:

How many grams are in 2.38 moles of NaCl?How many grams are in 2.38 moles of NaCl?

NaClgNaClmole

NaClgxNaClmoles 1391

5.5838.2

Mole to Mass Conversions #2Mole to Mass Conversions #2

Problem 2:Problem 2:

How many moles if 97.2 g of NaCl?How many moles if 97.2 g of NaCl?

NaClmolesNaClg

NaClmolexNaClg 66.1

5.58

12.97 1

2 Step Mole Problems2 Step Mole Problems

Mass Mass → Moles → Molecules→ Moles → Molecules

Molecules → Moles → MassMolecules → Moles → Mass

Gas volumes too!!!Gas volumes too!!!

MOLE ISLAND !!!MOLE ISLAND !!!

Mole IslandMole Island

Molar Mass

6.02

x 1

023

22.4 Liters GasVolumeReef