the mole unit 5. formula mass formula mass - also called: formula massmolecular mass molecular...
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The MoleUnit 5
Formula Mass
• Formula mass - also called:
formula mass molecular mass
molecular mass formula weight
formula weight molecular weight molecular weight molar mass
molar weight the mass of one mole of a compound,
atom or ion. (units: _g_ ) mol
Formula Mass:Example: Calculate the formula mass of the
following:
I Do: carbon tetrachloride Formula: CCl4
1 C: 12.011 g/mol4 Cl: 4 x 35.45 g/mol = 141.8 g/mol
Total mass: 153.81 g/mol
Formula MassExample: Find the formula mass of each of the
following:
We Do: arsenic trichloride: Formula: AsCl31 As: 74.922 g/mol3 Cl: 3 x 35.45 g/mol = 106.35 g/mol
Total mass: 181.27 g/mol
Formula MassExample: Find the formula mass of each of the
following:
You Do: potassium sulfide Formula: K2S
2 K: 2 x 39.098 g/mol = 78.196 g/mol1 S: 32.066 g/mol
Total mass: 110.262 g/mol
Measuring MatterThere are three ways to measure
matter: 1. By counting representative
particles: atoms – element
molecules- covalent compound
formula units- ionic compound
ions – anything with a charge
.
Al, Na, S, etc
PCl3,O2, CO2
AlCl3,K2O, Ba3P2
PO32-,K1+
2. By mass - in grams
3. By volume - in liters for gases (at STP)
Measuring Matter
1 mole of a compound = formula mass (in grams)1 mole of a compound = 6.02 x 1023 representative particles 1 mole of a gas (STP) = 22.4 liters
The mole is the link between grams, the number of representative particles and liters!
Remember: There are 4 different types of Representative ParticlesAtomsFormula unitsMoleculesIons
Identify the type of Representative Particle
• NaCl
• F2
• NH4+1
• CS2
• H2O
• Be
• CsF
Formula Units
Molecules
Ions
Molecules
Molecules
Atoms
Formula Units
Mole Road Map
Mole Practice: One Step Conversions: Remember to show all work using dimensional analysis.
I Do: How many moles are present in a tank of gas that contains 55.60 Liters?
Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
55.60 Liters = 2.48 moles of gas
Make sure to round the finalAnswer to the 100th place.Only the final answer!
Mole Practice: One Step Conversions: Remember to show all work using dimensional analysis.
We Do: How many moles are in 18.0 grams of sugar (C6H12O6)? Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
18.0 g C6H12O6
Make sure to round the finalAnswer to the 100th place.Only the final answer!
Add Masses of 6C + 12H + 6OYou must use all theNumbers from the Periodic Table
Mole Practice: One Step Conversions: Remember to show all work using dimensional analysis.
You Do: What is the mass in grams of 4.50 moles of barium sulfide? Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
4.50 mol BaS
Make sure to round the finalAnswer to the 100th place.Only the final answer!
Add Masses of 1 Ba + 1 SYou must use all theNumbers from the Periodic Table
Two and Three Step Conversions
I Do: What is the mass in grams of 5.02 x 1024 formula units of potassium phosphate? Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
5.02x1024 Formula units K3PO4
= 1117.98 g K3PO4
Two and Three Step ConversionsWe Do: How many molecules are in 198.5
grams of sodium chloride? Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
198.5g NaCl= 2.04x1024 Formula Units NaCl
Two and Three Step Conversions
You Do: How many Liters of gas is 3.21 x 1024 molecules of carbon monoxide?
Conversion Factors:
1 mole = formula mass 1 mole or g g 1 mole
1 mole = 6.022 x 1023 1 mole or 6.022 x 1023
particles 6.022 x 1023 1 mole
1 mole = 22.4 Liters gas 1 mole or 22.4 L 22.4 L 1 mole
3.21x1024 Molecules CO = 119.44 L CO