Year 9 Chemistry EoTT Revision

Which of the following statements describes a chemical change?

• Water boiling and turning into steam.

• Sand dunes changing shape due to the wind.

• Limestone caves forming due to acid rain.

• Sodium chloride dissolving in water to form a solution.

A chemical reaction always involves

• Physical changes to the reactants.

• The formation of new substances.

• A series of changes that are difficult to measure.

• Unable to determine from the given information.

Which statement best describes the Law of Conservation of Mass:

• The mass of reactants is the same as the mass of the products.

• The mass of the products is greater than the mass of the reactants.

• Mass of reactants is conserved and does not change.

• The number of atoms involved in a reaction can increase or decrease depending on the type of reaction.

pH is a measure of:

• The amount of hydroxide ions a substance contains.

• The concentration of a solution.

• How acidic or basic a substance is.

• Universal indicator.

Which of the following is NOT an acid?

• HNO3 

• NaCl

• HCl

• H2SO4

When hydrochloric acid is added to sodium hydroxide this type of reaction is called:

• A gas producing reaction.

• A combustion reaction.

• A neutralisation reaction.

• A substitution reaction.

A small piece of magnesium metal was dropped into some hydrochloric acid. All the gas produced was collected in a test tube. The gas collected would be:

• Hydrogen gas.

• Carbon dioxide gas.

• Oxygen gas.

• Water vapour.

A combustion reaction can be best described as:

• Exothermic

• Endothermic

• Neutralisation

• Physical change

Lemon juice has a pH of 2.0. It is: 

• an acid.

• a base.

• neutral.

• an alkali metal.

Identify the general form of all chemical equations:

• Acid + base = salt + water

• Reactants = products 

• Products = reactants

• Metal + water = metal hydroxide + hydrogen