Explain why the reactivity of Group 1 metals increases down the group.
24 marks
Use collision theory to explain why increasing temperature increases the rate of reaction.
33 marks
Explain what is meant by dynamic equilibrium.
44 marks
Explain how iron is extracted from iron(III) oxide in a blast furnace and why carbon can be used.
54 marks
Describe how crude oil is separated by fractional distillation.
64 marks
Describe how the Earth's early atmosphere changed to form today's atmosphere.
74 marks
Describe how potable water is produced from fresh water in the UK.
83 marks
Describe what you would see when potassium is added to water and write a balanced equation.
92 marks
60 cm³ of gas was collected in 30 s. Calculate the mean rate of reaction.
104 marks
N₂ + 3H₂ ⇌ 2NH₃ (forward reaction exothermic). Explain the effect on the yield of ammonia of increasing pressure and increasing temperature.
113 marks
Explain why aluminium is extracted by electrolysis rather than reduction with carbon.
123 marks
Explain why cracking is carried out.
136 marks
Evaluate the evidence that human activities are causing climate change.
143 marks
Explain why desalination is used in some countries and why it is expensive.
154 marks
Explain why chlorine displaces bromine from potassium bromide solution and write an ionic equation.
162 marks
45 cm³ of gas was collected in 25 s. Calculate the mean rate of reaction.
173 marks
Explain why the Haber process uses a temperature of about 450 °C.
Finished?
Answer every question to finish (17 left), or finish when the time’s up.
Score 0 / 60 · 0 of 17 marked
This paper is written by Plasmo in the style of the OCR GCSE Combined Science exam. It is not a past paper and is not produced or endorsed by the exam board.