This is the first set of problems on this topic, very fundamental to a lot of the rest of chemistry. You can find the set here.
Chemical formula, and chemical equations give you relationships. H2O means there’s two hydrogens for every one oxygen,
C8H18 + 12 1/2 O2 → 8CO2 + 9H2O
means one molecule of octane will react with 12 1/2 molecules of oxygen to produce 8 molecules of carbon dioxide and 9 molecules of water. It also tells you if you start with a kilogram of octane, you’ll end up with a bit more than a third of a gallon water as an end product.
Let’s say you want to produce aspirin in 1,000 kilogram batches. If you know the chemical equation, and how to calculate the molecular weights, you (and the Chemical Engineer in you) are golden. I hope you find this set enjoyable.
As always, if you have a question or would like to see another type of problem solved, you can reach me here: firstname.lastname@example.org.