A resource that can be used as a guide during a lesson or as a revision pack and is the first in a series of resources on stoichiometry. This resource focuses on calculating the masses and amounts of reactants and products of chemical reactions. The calculations contain step-by-step instructions including the processes of balancing equations using stoichiometric coefficients; the use of mole ratios to determine amounts in moles and the use of formulae to determine masses via methods involving conversion factors and without. This resource is aimed at AS level or equivalent chemistry students to introduce the topic of stoichiometry. This will act as a foundation before moving on to other aspects such as limiting and excess reactants in future resources.

A worksheet containing a template of a table that can be used for stoichiometric calculations involving a reactant and a product in a chemical reaction. Variables of mass, molar mass, mole ratio and amount in moles are clearly distinguished in different rows with blank boxes to allow students to write the relevant values for a question.

This resource can be used for revision purposes or to supplement lesson materials in GCSE (or equivalent) chemistry to introduce calculations that determine the mass, amount and number of particles of individual substances. This includes descriptions of the fundamental concepts of the mole and Avogadro’s constant. The conversion of number of particles to moles and vice-versa are demonstrated with atoms, molecules and formula units/ions. This includes explanations of methods with and without conversion factors conducive with various course specifications. The resource is provided in a word docx format with examples within the context of chemistry and more informal examples to aid understanding. Step-by-step examples of calculations are provided with the relevant formulae clearly presented before being applied within each calculation. This is in addition to practice questions for students to try with answers also provided in the resource.