You will complete 21 required practical activities if you are studying GCSE combined science: Trilogy. You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.
There will be a number of different types of practical based questions. Some will be on the set required practicals, some will cover the working scientifically terms and some will be on other science practicals which you might have done in class. Use all the information given in the question particularly any diagrams to help you understand what the question is about.
There are no required practical activities in the Organic chemistry section. However, there may be some questions drawing on practical skills relating to this topic within other questions on the paper.
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Describe how to test for an alkene, including the positive result. [2 marks]
Add bromine water 
It changes from orange to colourless 
A teacher tests the flammability of a liquid alkane.
This is the method used:
Suggest a reason for step 3. [1 mark]
So that the alkane in the bottle does not catch fire or so that the alkane cannot spill out if the bottle is knocked over. 
A student is attempting to crack the hydrocarbon molecules in paraffin, to make shorter hydrocarbons such as ethene and octane. The student has short hair and is wearing eye protection. State and explain one of the other safety precautions the student should consider during this experiment. [2 marks]
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
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, not a Bunsen burner. [1 mark]
Hydrocarbons are flammable, so if she uses a Bunsen burner the hydrocarbon might catch on fire.