Chemistry - 4 Chemical Calculations - 4.2 Equations and Calculations

You can determine the ratio of moles of each substance in a reaction using its balanced equation.

H₂ + Cl₂ → 2HCl

In this balanced equation, we have:

• one mole of hydrogen molecules

• one mole of chlorine molecules

• two moles of hydrochloric acid molecules

Using balanced equations to work out reacting masses:

moles = mass/Mr

• you will be given a balanced equation and the relative atomic masses of the important chemicals within

• you will be asked to solve for the mass of one of either the reactants or products.

• here is the method: