1.20 understand the term molar volume of a gas and use its values (24 dm3 and 24,000 cm3) at room temperature and pressure (rtp) in calculations.

MOLAR VOLUME OF A GAS:

- 1 mole of any gas is equal to 24 dm³ or 24,000 cm³ at room temperature (25'C) and pressure (1 atmosphere).
- Volume (dm³) = Moles of gas x 24
- Volume (dm³) = Mass of gas / Mr of gas x 24

REMEMBER DURING CALCULATIONS CONVERT cm³ TO dm³!!!!!

- For example:
What is the volume of 2 moles of chlorine?
Volume (dm³) = Moles of gas x 24
Volume (dm³) = 2 x 24 = 48 dm³

1.19 carry out mole calculations using relative atomic mass (Ar) and relative formula mass (Mr)

MOLE CALCULATIONS:

- To work out moles you divide the (Mass in grams (of an element / compound)) by (Relative formula / atomic mass (of an element / compound))
- The easy way to remember this is g, mr, mol. That is a triangle with a 'g' at the top, 'Mr' at the bottom left, and 'mol' at the bottom right.

1.18 understand the term mole as the Avogadro number of particles (atoms, molecules, formulae, ions or electrons) in a substance

MOLES:

- 1 mole is the same as 6.023 x 10²³ atoms / molecules.
- This number is Avogadro's number which can also be known as Avogadro's constant.
- The number shows how many particles (atoms, molecules, formulae, ions or electrons) in a substance.

1.17 understand the use of the term mole to represent the amount of substance

MOLES:

- A mole is a number which represents 6.023 x 10²³
- 1 mole of an atom / molecule has a mass equal to its relative formula mass.
- 12g of carbon contains 1 mole or 6.023 x 10²³ atoms / molecules. This means that 24g of carbon contains 2 moles of carbon.

1.16 calculate relative formula masses (Mr) from relative atomic masses (Ar)

RELATIVE FORMULA MASS (Mr):

- It is just all the relative atomic masses added together.
- MgCl2 is just 24 + (35.5 x 2) = 95
- C2H4(OH)2 is just (12 x 2) + (1 x 4) + ((16 + 1) x 2) = 62