4 marksFoundation
A student adds marble chips to hydrochloric acid and collects the carbon dioxide in a gas syringe.
.1Calculate the mean rate of reaction in the first 30 seconds.
[2 marks] .2Give the earliest time in the table by which the reaction had stopped.
[1 mark] .3Describe how the rate changes during the reaction.
[1 mark] 4 marksFoundation
Some substances are listed below.
Copper, carbon dioxide, air, sodium chloride.
.1Which substance is an element?
[1 mark] .2Which substance is a mixture?
[1 mark] .3Give the number of different elements in the formula
CaCO3. .4A student has a mixture of sand and water. Choose the best method to get the sand.
[1 mark] 4 marksFoundation
Magnesium reacts with oxygen to form magnesium oxide, an ionic compound.
The electron structure of magnesium is 2,8,2 and of oxygen is 2,6.
.1Describe what happens to the electrons when magnesium reacts with oxygen.
[2 marks] .2What are the charges on the ions in magnesium oxide?
[1 mark] .3Name the type of force that holds the ions together.
[1 mark] 3 marksFoundation
A student tests two samples of a white solid. The pure solid melts at 122 °C.
Sample A melts at 122 °C. Sample B melts between 115 °C and 119 °C.
.1Which sample is impure?
[1 mark] .2Give the meaning of a pure substance in chemistry.
[1 mark] .3Which of these is a formulation?
[1 mark] 3 marksFoundation
Acids react with metals, bases and carbonates to make salts.
.1Name the salt made when magnesium oxide reacts with hydrochloric acid.
[1 mark] .2Name the salt made when sodium hydroxide reacts with sulfuric acid.
[1 mark] .3Name the gas produced when calcium carbonate reacts with hydrochloric acid.
[1 mark] 