Practical questions

You will complete 12 required Specified Practical Activities if you are studying GCSE Chemistry, and 27 if you are studying GCSE Combined Science (nine of these are in Chemistry). These help you develop some key practical techniques in Chemistry.

You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.

There are no Specified Practical Activities in the 'Carbon compounds' section.

Sample question 1 - Foundation

Question

A teacher has some liquid fractions obtained from crude oil.

She wants to show her students how easily the different fractions catch fire.

This is the method used.

  1. use a teat pipette to remove a small amount of one of the fractions from its bottle
  2. place the fraction on a watch glass
  3. screw the lid back onto the bottle
  4. use a splint to try to set fire to the alkane
  5. repeat steps 1 to 4 with the other fractions

Suggest a reason for step 3. [1 mark]

This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.

So that the fraction in the bottle does not catch fire or so that the fraction cannot spill out if the bottle is knocked over. [1]

Sample question 2 - Foundation

Question

The fractions obtained from crude oil are used as fuels.

The temperature rise in water when liquid fuels burn can be found using the equipment shown in the diagram.

Apparatus for calorimetry: a calorimeter containing water and a thermometer sits over a spirit burner

A teacher compares the temperature rise produced in the water when two different liquid fuels burn.

State two factors that the student teacher must keep the same in both experiments to ensure a fair comparison. [2 marks]

Question courtesy of Eduqas.

Any two from:

  • mass/volume of water
  • height of container above wick
  • length of wick/height of flame
  • the container needs to be the same shape/size/material
  • same number of moles/amount of alcohol

[2]

Sample question 3 - Higher

Question

A teacher wants to heat a liquid hydrocarbon to 50°C.

He pours 5 cm3 of the hydrocarbon into a test tube. Then he places the test tube in a beaker of hot water.

Suggest why the teacher uses hot water to heat the hydrocarbon and not a Bunsen burner. [1 marks]

Question courtesy of Eduqas.

Hydrocarbons are flammable, so if she uses a Bunsen burner the hydrocarbon might catch on fire. [1]

Sample question 4 - Higher

Question

A sample of decane, C10H22, was cracked using the apparatus shown in the diagram

Two bunsen burners heat ceramic wool in decane and porous pot, in a test tube. The air is passed through a tube into an upturned test tube containing water.

This produced a mixture of products, including ethene.

Explain how ethene is produced using the apparatus shown in the diagram. [3 marks]

Question courtesy of Eduqas.

  • when the decane is heated it vaporises/turns to a gas [1]
  • decane vapour/gas breaks down as it comes into contact with hot porous pot [1]
  • large molecules of decane produce smaller molecules, including ethene [1]