AQA GCSE Chemistry (8462), Higher tier · Chemical analysis › Purity, formulations and chromatography
Practise Formulations. 12 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
(a) What is a formulation? Tick (✓) one box.[1]
A mixture that has been designed as a useful product
A pure compound made in a laboratory
Any mixture of substances found in nature
An element that has been purified
(b) Which two of the following are formulations? Tick (✓) two boxes.[2]
Distilled water
Paint
Oxygen gas
Medicine tablet
Copper wire
(c) Formulations are made by mixing the components in carefully measured quantities. Give the reason why.[1]
Show the answer and mark scheme
(a)Answer: A mixture that has been designed as a useful product
(b)Answer: Paint; Medicine tablet
(c)
so that the product has the required properties / so each component can do its job
Question 2Medium5 marks
Paint is a formulation. {table} shows the components of one paint.
[object Object]
(a) Suggest the purpose of the solvent in the paint.[1]
(b) A tin contains 2.5 kg of the paint. Calculate the mass of pigment in the tin.[2]
(c) Explain why paint is described as a formulation.[2]
Show the answer and mark scheme
(a)
makes the paint runny / easy to spread / dissolves or carries the binder (and then evaporates)
(b)Answer: 0.55 kg
22 ÷ 100 × 2.5
0.55 (kg)
(c)
it is a mixture that has been designed as a useful product
each component has a particular purpose / the components are mixed in measured quantities to give the required properties
Question 3Hard7 marks
A fuel company sells a fuel formulation called E10, which is 90% petrol and 10% ethanol by volume. A customer buys 40 litres of E10.
(a) Calculate the volume of ethanol in the 40 litres of fuel.[1]
(b) The density of ethanol is 0.79 kg/litre and the density of petrol is 0.74 kg/litre. Calculate the percentage by mass of ethanol in E10. Give your answer to 3 significant figures.[3]
(c) A different fuel, E85, is 85% ethanol and 15% petrol by volume. Explain why a car engine designed for E10 might not run properly on E85, even though both are formulations of the same two substances.[2]
(d) Suggest one reason why ethanol is blended with petrol to make these fuel formulations.[1]
Show the answer and mark scheme
(a)Answer: 4 litres
4 (litres)
(b)Answer: 10.6%
mass of ethanol in 1 litre of E10 = 0.10 × 0.79 = 0.079 (kg) and mass of petrol = 0.90 × 0.74 = 0.666 (kg)
percentage = 0.079 ÷ (0.079 + 0.666) × 100
10.6 (%)
(c)
the proportions of ethanol and petrol are very different (much more ethanol in E85)
the engine is designed / set up for the properties of the E10 mixture, so a very different mixture may not burn correctly and could damage the engine
(d)
ethanol can be made from plant material (a renewable resource), so blending it reduces the amount of petrol needed from crude oil, a finite resource