1. Unit 2: Atomic Theory & Structure
Section 3: Molar Mass Conversions

2. mass of one mole of particles
Molar Mass:
mass of one mole of particles
units:
grams per mole
(g/mol)
6.02 x 1023
particles 1
mole

3. Periodic
Table
55.85g
12.01g
One molar mass of carbon, sulfur, mercury, and iron are shown. Each of the quantities contains one mole of the element. Applying Concepts How many atoms of each element are shown?
32.07g
200.59g

4. Use molar mass to convert between mass and moles.
(get MM from the PT)
Type 3
mol grams
Given mol x MM of given = ______
1 mol
Type 4
grams mol
given g x 1 mol = _____ mol
MM (g)

5. Type 3
mol grams
What is the mass of 9.45 mol of aluminum, Al?
9.45 mol x
26.98g
_______ =
1 mol
255 g

6. Find the mass, in grams, of 0.0452 mol C20H42 (wax).
Type 3
mol grams
Find the mass, in grams, of mol C20H42 (wax).
(MM = g/mol)
mol x g
_______ =
1 mol
12.8 g

7. How many moles are in 92.2 g of Fe2O3 ?
Type 4
grams mol
When iron is exposed to air, it corrodes to form red-brown rust which is iron(III) oxide (Fe2O3).
How many moles are in 92.2 g of Fe2O3 ?
MM = g/mol
92.2 g x
______= g
1 mol
0.577 mol
Rust weakens an iron chain.

8. Find the number of moles in 258 g N2O.
Type 4
grams mol
Find the number of moles in 258 g N2O.
MM = g/mol
258 g x
______=
44.02 g
1 mol
5.33 mol

9. 1. Where do you look to get the molar mass of an element?
Quick Quiz!
1. Where do you look to get the molar mass of an element?
Avogadro’s number
the periodic table
your neighbor’s paper
your face

10. Quick Quiz.
2. Calculate the mass in grams of a sample containing 1.85 mol of water.
1.11 x 1024 g
33.3 g
18.02 g
8460 g
MM = g/mol

11. Quick Quiz.
3. Calculate the number of moles in a spoonful of table salt (NaCl) having a mass of 3.50 g.
208 mol
2.58  103 mol
mol
17.0 mol
MM = g/mol