Molar Mass and Conversions Notes
How to find molar Mass:
Example and steps: Ca(OH)2
Step 1: Identify the different elements in the given compound and the number of moles
for each one. (remember to distribute if you have parenthesis)
1 mol Ca x
2 mol O x
2 mol H x
40.08 = 40.08
16.00 = 32.00
1.01 = 2.02
74.10 g/mol
Step 2: Multiply the number of atoms of each element by that element’s atomic mass.
(Round the masses to the nearest hundredth—2 numbers after the decimal)
Step 3: Add all multiplied amounts and place the proper unit (grams per mole – g/mol)
Conversions:
Mole (given) to Mass (answer)
Given(mol) molar mass (g)
1 mole
Answer (g)
Mass (given) to Mole (answer)
Given (g)
1 mol
Molar mass (g)
Answer (mol)
Mole to Particles (which could molecules or formula units)
Given (mol)
6.02 x 10 23 (particles)
1 mol
Answer (particles)
Mass to Particles
Given (g)
1 mol
Molar mass (g)
6.02 x 10 23 (particles)
1 mole
Answer (particles)
Particles to Mass
Given (particles)
1 mol
6.02 x 10 23 (particles)
molar mass (g)
1 mol
Answer (g)
Molar Mass and Conversions Notes
How to find molar Mass:
Example and steps: Ca(OH)2
Step 1: Identify the different elements in the given compound and the number of moles
for each one. (remember to distribute if you have parenthesis)
1 mol Ca x
2 mol O x
2 mol H x
40.08 = 40.08
16.00 = 32.00
1.01 = 2.02
74.10 g/mol
Step 2: Multiply the number of atoms of each element by that element’s atomic mass.
(Round the masses to the nearest hundredth—2 numbers after the decimal)
Step 3: Add all multiplied amounts and place the proper unit (grams per mole – g/mol)
Conversions:
Mole (given) to Mass (answer)
Given(mol) molar mass (g)
1 mole
Answer (g)
Mass (given) to Mole (answer)
Given (g)
1 mol
Molar mass (g)
Answer (mol)
Mole to Particles (which could molecules or formula units)
Given (mol)
6.02 x 10 23 (particles)
1 mol
Answer (particles)
Mass to Particles
Given (g)
1 mol
Molar mass (g)
6.02 x 10 23 (particles)
1 mole
Answer (particles)
Particles to Mass
Given (particles)
1 mol
6.02 x 10 23 (particles)
molar mass (g)
1 mol
Answer (g)