Chemistry > EXAM REVIEW > AQA CHEMISTRY 2 COMPLETE SOLUTION GUIDE (All)

AQA CHEMISTRY 2 COMPLETE SOLUTION GUIDE

Document Content and Description Below

AQA CHEMISTRY 2 COMPLETE SOLUTION GUIDE FOR STUDY AND EXAM PREPARATIONS Masses of atoms and moles: • Relative atomic mass (RAM / Ar): o Instead of working out how much of an element is needed fo... r a chemical reaction with the actual mass of an element we use the relative mass. o The relative mass of an element is its mass number. For example, carbon’s mass number is 12 so therefore its RAM is also 12. This is because it has 6 protons and 6 neutrons; we do not count the electrons as their mass is negligible. o The RAM also takes into account any isotopes of the element as it is the average mass of isotopes in the proportions in which they are usually found compared with the standard mass of the element. o The relative ionic mass is the same as the RAM since the mass of the electrons is negligible. • Relative formula mass (RFM / Mr): o The RAM of an element can help to work out the RFM. By adding together the RAM of all the elements in the formula you can get the RFM.  For example: → RFM of NaCl = 23 + 35.5 = 58.5 → RFM of H2 0 = (1x2) + 16 = 18 • Relative atomic / formula mass in grams = mole o For example,  The relative atomic mass of carbon in grams is 12 grams = One mole of carbon is 12 grams. • The mole of any element or compound has 6.02 x 10²³ (602,000,000,000,000,000,000,000) atoms, ions or molecules. This number is called Avogadro’s number. [Show More]

Last updated: 2 years ago

Preview 1 out of 32 pages

Buy Now

Instant download

We Accept: