4 marksFoundation
A teacher adds a small piece of lithium to a trough of water containing universal indicator.
.1Give two observations the students would see.
[2 marks] .2Complete the word equation: lithium + water → lithium hydroxide + ______
[1 mark] .3The teacher repeats the demonstration with potassium. Predict how the reaction compares.
[1 mark] 3 marksFoundation
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] 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] 2 marksFoundation
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] 3 marksFoundation
Chemical reactions can transfer energy to or from the surroundings.
.1Which two reactions are exothermic? Tick two boxes.
[2 marks] .2Give one everyday use of an endothermic reaction.
[1 mark] 