6 marksFoundation and HigherRequired practical 095.4.3.4 Electrolysis of aqueous solutions
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]6 marksFoundation and HigherRequired practical 105.5.1.1 Energy transfer during exothermic and endothermic reactions
A student wants to investigate how the volume of sodium hydroxide solution added to 25 cm³ of dilute hydrochloric acid affects the temperature change.
Plan an investigation the student could carry out.
Include the variables to control and how to make the results as accurate as possible.
[6 marks]4 marksFoundation5.1.1.1 Atoms, elements and compounds5.1.1.2 Mixtures
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 Higher5.2.2.6 Giant covalent structures5.2.2.5 Polymers
Silicon dioxide (silica) melts at 1710 °C. Poly(ethene) softens at about 120 °C. Methane boils at −162 °C.
Explain the differences in these temperatures.
Refer to the structure and bonding of each substance.
[6 marks]6 marksFoundation and HigherRequired practical 085.4.2.3 Soluble salts
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]