An A-Level Chemistry resource on calculating Amount of substance (Moles). The worksheet is differentiated with each section increasing in difficulty. The resource is editable and answers are included with each section so that students can check their progress. This is the first half of this resource, the 2nd half is also available on this website with 2 more pages on atom economy, empirical formulae, percentage yield etc. The complete set has 16 sections in total. If you like this resource there will soon be others I will be uploading onto this website on calculating entropy, pH, Kc, Kp, Grignard reagents, inorganic formulae, Ecell, pV = nRT etc.