Mole: the unit of amount of substance in chemistry, its symbol is mol.

Stoichiometry: the relationship between the number of moles of reactant and the number of moles of products in the same chemical reaction.

Relative Atomic Mass: the mass of one atom of an element compared to 1/12th of the mass of one Carbon-12 atom.

Relative Molecular Mass: the mass of one molecule of an element/compound compared to 1/12th of the mass of one Carbon-12 atom.

Relative Formula Mass: the molecular mass for ionic compounds.

Avagadro’s number/constant: one mole of any substance contains 6x1023 particles.

Empirical Formula: the simplest ratio of atoms or elements present in a compound.

Molecular Formula: shows the number of atoms of each element in a compound.

Molar Mass: Mass of 1 mole of a substance.

Molar Volume: Volume occupied by 1 mole of gas. At r.t.p, one mole of any gas occupies 24 dm3.

Concentration: Amount of solute dissolved per unit volume of the solution.

Yield: the amount of product formed in a reaction.

Theoretical yield: the calculated amount of product that would be obtained if the reaction would be complete with no external factors acting upon it.

Actual yield: the amount of product formed in a reaction..

Percentage yield: the relationship between the actual and theoretical yield.

Percentage purity: the percentage of the mass of pure substance upon mass of the whole sample.

Limiting reactant: the reactant that determines the amount of product formed because of having fewer moles.

Excess reactant: the leftover reactant after the reaction has stopped.