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] 6 marksFoundation and Higher
A student investigates what is produced when aqueous solutions of copper chloride and sodium chloride are electrolysed using inert electrodes.
Plan an investigation to find the products at each electrode for both solutions.
Include how you would identify any gases.
[6 marks]4 marksFoundation and Higher
A student heats 2.40 g of magnesium ribbon in an open crucible. It all reacts to form 4.00 g of magnesium oxide.
2Mg+O2→2MgO.1Calculate the mass of oxygen that reacted with the magnesium.
[1 mark] .2The student says: "The mass went up, so mass was not conserved."
Explain why the student is wrong.
[2 marks] .3The student repeats the experiment in a sealed container full of air and weighs the whole container. Predict what happens to the total mass.
[1 mark] 4 marksFoundation and Higher
Aluminium oxide is an ionic compound. It contains
Al3+ and
O2− ions.
.1Write the formula of aluminium oxide.
[1 mark] .2Describe the structure of aluminium oxide.
[3 marks] 6 marksFoundation and Higher
A student wants to make pure, dry crystals of copper sulfate from copper oxide (an insoluble black powder) and dilute sulfuric acid.
Plan a method the student could use.
In your answer, explain the reason for each step.
[6 marks]