Transcript Mole Conversions

Review: Molar Mass of
Compounds

Ex. Molar mass of CaCl2
20
Avg. Atomic mass of Calcium = 40.08g
 Avg. Atomic mass of Chlorine = 35.45g


Molar Mass of calcium chloride =
40.08 g/mol Ca + (2 X 35.45) g/mol Cl
 _110.98______ g/mol CaCl2
Ca
40.08
17
Cl
35.45
Practice

Calculate the Molar Mass of calcium
phosphate
Formula =
 Ca3(PO4)2
Masses elements:
Ca = 40.08g/mole
P = 30.97 g/mole
O = 16.00 g/mole
 Molar Mass =

(40.08 g/mole)(3) + (30.97 g/mole)(2) + (16
g/mole)(8)
= 310.18 g/mole
Mole Conversions
Atoms or
Molecules
Divide by 6.02 X 1023
Multiply by 6.02 X 1023
Moles
Multiply by
atomic/molar mass
from periodic table
Divide by
atomic/molar mass
from periodic table
Mass
(grams)
Review
 5.7
kg = ?? mg

3.5 dozen roses = ?? Roses

2.5 mol roses = ?? Roses (use Avogadro's #)
Practice

Find the mass of 0.89 mol of CaCl2.

Find the molar mass of the compound:

Make the conversion:
Practice

A bottle of PbSO4 contains 158.1 g of
compound. How many moles of PbSO4 are
in the bottle?
Calculations
molar mass
Grams
Avogadro’s number
Moles
particles/formula
units/atoms
Everything must go through
Moles!!!
Practice

Determine the number of atoms that are in
0.58 mol of Se.
Practice

How many moles of barium nitrate (BaNO3)
contain 6.80 x 1024 formula units?
Calculations
molar mass
Grams
Avogadro’s number
Moles
particles/formula
units/atoms
Everything must go through
Moles!!!

2.5 g Roses = ?? Roses

Atomic mass of 1 Rose is 3.0 g/mol
Multi-step Practice

How many molecules are in 5.1g of TiO2?
Multi-step Practice

If you burned 6.10 x 1024 molecules of ethane
(C2H6), what mass of ethane did you burn?
Molar Volume

Definition: The volume of one mole of an
ideal gas at standard conditions (STP) equal
to 22.4 L.

STP = standard temperature and pressure
which is 0ºC and 1 atmospheric pressure

1 mole gas at STP = 22.4 L
Practice

A container with a volume of 893L contains
how many moles of air at STP?
Practice

A chemical reaction produced 0.37 mol of N2
gas. What volume will the gas occupy at
STP?