MOLAR MASS AND MOLE CALCULATIONS

Molar Mass

Molar mass is the mass in grams of one mole of particles (atoms, ions, molecules, formula units).

Equal to the numerical value of the average

atomic mass (get from periodic table)

1 mole of C atoms = 12.0 g

1 mole of Mg atoms = 24.3 g

1 mole of Cu atoms = 63.5 g So, Molar Mass is the atomic mass expressed

in units grams/mole (g/mol)

Molar Mass

Chlorine has an atomic mass of 35.453 amu. So what is its molar mass?

35.453 grams per mole

The number is the same, just change the unit.

Molar Mass

How do we find the molar mass of a compound? Find the molar mass of each element

in the compoundDetermine how many of each

element are in the compound.Multiply the number of each element

by its molar mass. Add these mumbers.

Molar Mass

In one mole of Aluminum Bromide, there is 1 mole of

aluminum atoms and 3 moles of bromine atoms.

Aluminum Bromide

AlBr3

Molar Mass

To find the molar mass of AlBr3, we do the following:

1 mol Al x 26.9815 g/mol Al = 26.9815 g Al

3 mol Br x 79.904 g/mol Br = 239.712 g Br

26.9815 g Al + 239.712 g Br = 266.6935 g AlBr3 per mole or 266.6935 g/mol AlBr3

Mole Calculations

M

mn

Where, n is the # of moles (mol) m is the mass (g)M is the molar mass (g/mol)

Relationship Between Moles, Mass and Particles

Mole Calculations

What is the mass of 4.72 x 1023 formula units of chromium (III) iodide?