moles objective: to practise calculations involving a mole of a substance

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Moles Objective: To practise calculations involving a mole of a substance.

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Page 1: Moles Objective: To practise calculations involving a mole of a substance

Moles

Objective:

To practise calculations involving a mole of a substance.

Page 2: Moles Objective: To practise calculations involving a mole of a substance

Calculating the mass of a mole

Task 1

For an element, a mole is the relative atomic mass expressed in grams. The relative atomicmass of hydrogen is 1, the same as the mass number for hydrogen. So the mass of one mole of hydrogen is 1 g.

Element Relative atomic mass

Mass of one mole

Hydrogen 1 1g

Carbon

Oxygen

Magnesium

Page 3: Moles Objective: To practise calculations involving a mole of a substance

Calculating the mass of a mole

Task 2

For a compound, a mole is the relative formula mass expressed in grams.

Compound Formula Relative formula mass

Massof one mole

Sodium fluoride

NaF 23 + 19 = 42 42 g

Water

Carbon dioxide

Calcium oxide CaO

Page 4: Moles Objective: To practise calculations involving a mole of a substance

Moles glossary

Define the following terms:

• Relative Atomic Mass.

• Relative formula Mass.

• A mole.

Page 5: Moles Objective: To practise calculations involving a mole of a substance

What is a mole?

A mole is the relative atomic mass or formula mass expressed in grams.

A mole of any substance always contains the same number of particles.

A mole of any element or compound contains 6.02 x 1023 atoms, ions or molecules. This is called Avogadro’s number.

Page 6: Moles Objective: To practise calculations involving a mole of a substance

Moles calculations

mass (g)

Moles = molar mass (g)

Mass (g) = moles x molar mass (g)