The Mole
A measurement of matter.
The Mole
• What is the mole used for?
– The mole is used to measure matter.
– Imagine trying to count atoms in a substance.
The Mole
• How do we find one mole?
– You use Avogadro’s number.
– What is this number
• 6.022 X 10 23
The Mole
• What is the equation?
– Moles = particles / Avogadro’s number
– Particles = moles x Avogadro’s number
– How many moles are in 2.3 X 10 20 particles
of copper?
– How many particles are in 1.2 moles of silver?
The Mole
• How many grams are in a mole?
– Trick question: depends on the substance!
– Molar mass is equal to the sum of atomic
masses of each atom in a substance.
– What is the molar mass of water?
• 18 g/mol
The Mole
• How can we convert grams into moles?
– Moles = grams given/molar mass
– How many moles are in 12 grams of NaCl?
• .21 mol
The Mole
• How do we find empirical formula?
– % to mass
– Mass to moles
– Divide by small
– Multiply til whole
The Mole
• How do we convert empirical formula to
molecular formula?
– You compare the molecular mass of each and
find the ratio.
– You multiply the empirical formula by the
whole number ratio.
The Mole
• What are hydrates?
– A hydrate is a compound that is stable with
water.
– FePO4 x 4H2O
– Iron (III) phosphate tetrahydrate
The Mole
• How do we find the hydration level given
data?
– Convert the masses into moles and compare
the numbers.