Year 10 Chemical Reactions

The reactions in the image show the insoluble compounds formed when sodium hydroxide is added to metal solutions. These are examples of:

• precipitation reactions

• decomposition reactions

• neutralisation reactions

• synthesis reactions

Hydrochloric acid (HCl) is an example of a:

• weak acid

• strong acid

• weak base

• strong base

On the pH scale:

• neutral substances are 7, basic substances are less than 7 and acidic substances are greater than 7.

• neutral substances are 7, acidic substances are 0 and basic substances are 14.

• neutral substances are 0, acidic substances are between 0 and 7, and basic substances are greater than 7.

• neutral substances are 7, acidic substances are less than 7 and basic substances are greater than 7.

An indicator:

• is a base that dissolves in water

• is a substance that changes colour in the presence of an acid or a base

• neutralises an acid

• determines whether a substance is an acid or a base by taste or smell

The combustion of propane can be written by the following chemical equation:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

What are the products in this equation?

• C₃H₈ and 3CO₂

• 3CO₂ and 4H₂O

• C₃H₈ and 5O₂

• 4H₂O and 5O₂

2H₂(g) + O₂(g) → 2H₂O(l)

The above equation is what type of reaction?

• composition

• decomposition

• respiration

• synthesis

Which of these is an example of an acid you would find in your household?

• soap

• vinegar

• ammonia

• bleach

Complete the equation: acid + base → salt + _______

• hydrogen

• oxygen

• carbon dioxide

• water

What does the law of conservation of mass state?

• All atoms will always have exactly the same mass because they are all made from protons, neutrons and electrons.

• The mass of the chemicals involved in a chemical reaction must equal 1 kg.

• The total mass of the chemicals involved in a chemical reaction is not changed.

• Mass within the living world is precious and must be conserved.

2H₂O₂(aq) → 2H₂O(l) + O₂(g)

The equation shown here is a:

• decomposition reaction

• neutralisation reaction

• breakdown reaction

• synthesis reaction