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

2. Calculating the mass of a mole Task 1 For an element, a mole is the relative atomic mass expressed in grams. The relative atomic mass of hydrogen is 1, the same as the mass number for hydrogen. So the mass of one mole of hydrogen is 1 g. ElementRelative atomic mass Mass of one mole Hydrogen11g Carbon Oxygen Magnesium

3. Calculating the mass of a mole Task 2 For a compound, a mole is the relative formula mass expressed in grams. CompoundFormulaRelative formula mass Massof one mole Sodium fluoride NaF23 + 19 = 4242 g Water Carbon dioxide Calcium oxideCaO

4. Moles glossary Define the following terms: Relative Atomic Mass. Relative formula Mass. A mole.

5. 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 10 23 atoms, ions or molecules. This is called Avogadro’s number.

6. Moles calculations mass (g) Moles = molar mass (g) Mass (g) = moles x molar mass (g)