Mole & Molar Mass
Mole (mol): the amount of material counting 6.02214 × 1023 particles
The value of the mole is equal to the number of atoms in exactly 12 grams of pure
carbon-12.
12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms
The number of particles in 1 mole is called Avogadro’s Number (6.0221421 x 1023).
6.022 ×1023atoms
1 mol or 1 mol
6.022 ×1023 atoms
Converting between Number of Moles and Number of Atoms
Calculate the number of atoms in 2.45
mol of copper.
A silver ring contains 1.1 x 1022 silver
atoms. How many moles of silver are in
the ring?
2.45 mol Cu × 6.022 ×1023 atoms
1 mol
= 1.48 × 1024 atoms Cu
1.1 ×1022 atoms Ag × 1 mol
6.022 ×1023 atoms
= 1.8 × 10-2 mol Ag
Molar Mass: the mass of 1 mol of atoms of an element
An element’s molar mass in g/mol is numerically equal to the element’s atomic mass in
amu.
1 mol C
12.01 g C or 12.01 g C
1mol C
Converting between Mass and Number of Moles Converting between Mass and Number of Atoms
Calculate the moles of carbon in 0.0265 g of
pencil lead. How many aluminum atoms are in a can
weighing 16.2 g?
0.0265 g C × 1 mol C
12.01 g C
= 2.21 × 10-3 mol C
16.2 g Al × 1 mol Al
26.98 g Al × 6.022 ×1023 atoms
1 mol
= 3.62 × 1023 atoms Al
Atoms
mol Cu
g Al mol Al atoms Al
mol Ag Atoms Ag
mol C g C
