25 Jun 2020
Stoichiometry TYS questions – Combined Chemistry
There is no stoichiometry without try: try out questions from the O Level Combined Chemistry papers
17 Jun 2020
Stoichiometry: Percentage yield & percentage purity
Be 100% sure about how to calculate percentage yield and percentage purity
12 Jun 2020
Salt preparation TYS questions
It's big brain time, as you think backwards from the salt in question to infer the reagents and method
3 May 2020
Stoichiometry & the mole concept prelim questions
Learn stoichiometry and the mole concept by solving problems taken from O Level prelim papers. Answers and explanations are included.
1 May 2020
Percentage mass & empirical formula
Calculate how each element in a compound is pulling its weight, and use this to find the chemical formula empirically
30 Apr 2020
Relative atomic mass & molecular mass
Unit-less but meaningful: making sense of the mass of an atom with ratio
24 Apr 2020
Solution concentration & titration
Sorry, we don't have 25% sugar here. How about 100 g/dm3 or 0.292 mol/dm3?
23 Apr 2020
Stoichiometry: Mole ratio & limiting reactant
Look into the future and predict the amount of product formed, by identifying the mole ratio and limiting reactant
6 Apr 2020
Practise how to write chemical formula
Can you infer the formulae of ionic compounds, based on the charges of their constituent ions?