Calculations for AS and A level Chemistry
Being confident in tackling different types of mole calculation is the foundation upon which much of A level chemistry stands
From the blog
Finding the formula of a hydrated salt
Finding the formula of a hydrated salt is no different than determining the empirical formula of any other compound –
Determining the limiting reactant in a reaction
Limiting reactant problems follow on directly from reacting mass calculations. In these questions, you have to figure out which reactant
Continue readingDetermining the limiting reactant in a reaction
Percentage yield calculations
Percentage yield is one of many deciding factors in determining whether or not a reaction is economically viable. It compares
Reacting mass calculations
The key to reacting mass calculations at A level is to have a foolproof method for setting them out so
Empirical vs. molecular formulae
Empirical formula: simplest ratio of the atoms of different elements in a compound Molecular formula: the actual number of each
Working with different units in chemistry
Factor Name Unit Common examples 106 mega M 103 kilo k kg 10-1 deci d dm 10-2 centi c cm
Atom economy
Atom economy or percentage atom economy is simply a measure of how ‘green’ a chemical process is – it essentially
Significant figures in chemistry
Rule 1: when adding or subtracting numbers, the answer should be quoted to the least number of decimal places in
Avogadro’s number and the mole
Often students arrive at A level knowing how to calculate the number of moles of a substance but with a