4 marksFoundation5.6.1.1 Calculating rates of reactions
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] 3 marksFoundation5.7.1.1 Crude oil, hydrocarbons and alkanes5.7.1.2 Fractional distillation and petrochemicals
Crude oil is a mixture of hydrocarbons.
.1Define the term hydrocarbon.
[1 mark] .2Butane has 4 carbon atoms. Write the formula of butane.
[1 mark] .3Which fraction is used as fuel for aircraft?
[1 mark] 3 marksFoundation5.8.1.1 Pure substances5.8.1.2 Formulations
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 marksFoundation5.10.1.1 Using the Earth's resources and sustainable development5.10.1.2 Potable water
Humans use the Earth's resources for food, warmth, shelter and transport.
.1Which resource is finite?
[1 mark] .2Define potable water.
[1 mark] .3Name one substance or method used to sterilise water.
[1 mark] 2 marksFoundation5.9.1.1 The proportions of different gases in the atmosphere
Dry air is a mixture of gases.
.1Which gas makes up about four-fifths of the air?
[1 mark] .2A classroom holds 200 m³ of air. Calculate the approximate volume of oxygen in the room, using oxygen as one-fifth of the air.
[1 mark] 