the reactant that completely reacts, thereby determining the maximum amount of product that can be formed in a chemical reaction. All other reactants will be present in excess

used to determine the size of one quantity in relation to another

the molar ratio of the reactants and products in a chemical reaction

A mole of a substance is 6.02 × 10²³ particles of it. The mass of a mole of a substance is its relative mass in grams.

describes a reaction using a symbol equation with coefficients which ensure there are equal numbers of atoms of each element on both sides of the equation

Determining an equation experimentally: magnesium oxide

Combined science

Three types of chemical reaction

Conservation of mass

Balancing equations

The mole

Moles and masses

Uncertainties in measurements: chemistry

Representations of a mole

Mass in a chemical reaction: using moles

Limiting reactants

Determining an equation from given values

Determining an equation experimentally: sodium hydrogencarbonate

In the Making salts unit, pupils will learn about the production of pure salts, concentration and strength of acids, and what makes acids acidic and how bases can neutralise them.

In the Understanding Chemical Reactions unit, pupils learned about how atoms rearrange during chemical reactions and the conservation of mass.

This unit covers writing chemical formulae, balancing equations, and using the conservation of mass. It includes calculating moles, empirical formulae, relative formula masses, and theoretical yields. Emphasis is on stoichiometry, concentration, gas volumes, and using standard form.

Calculations involving masses

Physical activity and equipment requiring safe use

The molar ratio of the reactants and products in a chemical reaction.

Substance that completely reacts during a reaction.

Match the following terms to the correct definition.

Heating magnesium in a Bunsen burner flame.

Heating magnesium in a crucible with a lid.

Heating magnesium in an evaporating basin.

Which of the following is an example of a closed environment?

Protects scientists from the bright light produced.

Which of the following are advantages of using a crucible and lid to heat magnesium?

Use the following information to calculate the mass of oxygen that reacted with the magnesium to form magnesium oxide. Mass of magnesium = 4.78 g; mass of magnesium oxide = 7.56 g. 
2Mg + O₂ → 2MgO

When magnesium is heated in a crucible the lid is occasionally opened. This makes sure the oxygen ...

Calculate the amount of magnesium oxide in 7.56 g. Relative atomic masses: Mg = 24; O = 16.

Reaction in which oxygen atoms bond to the elements of the reactants.

The reactant that completely reacts during a reaction.

A reactant that remains at the end of a reaction.

How many moles of each chemical we need to react to make the products.

True of false? Combustion is an example of an oxidation reaction.

copper carbonate → carbon dioxide + copper oxide 

Which of the following equations describes an oxidation reaction?

The formula for glucose is C₆H₁₂O₆. Which of the following statements about glucose are correct?

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Which of the following are examples of oxidation reactions?

What is the ratio of oxygen to carbon dioxide in the following equation?
CH₄ + 2O₂ → CO₂ + 2H₂O

Determining an equation experimentally: magnesium oxide

Lesson outcome

Content guidance