Are you familiar with what’s tested in A Level H2 Chemistry Practical or H2 Chemistry Paper 4?
For students taking H2 Chemistry, Chemistry practical or paper 4 is one of the papers they need to take. This practical exam accounts for 55 marks or 20% of the total chemistry score.
There are usually 4 questions in this paper, and these questions are typically (note the word typically):
- titration question
- qualitative analysis
- physical chemistry (typically reaction kinetics, chemical energetics or equilibrium)
- planning question
Titration Question in A Level H2 Chemistry Practical
In titration, students are expected to find the concentration of a solution, but titrating it against a known concentration of another solution. In A Level titration questions, it is also common for students to be asked to prepare standard solution using a graduated flask.
Titration reactions are often acid- base or redox. Acid- base titrations would require an indicator (e.g. methyl orange or phenolphthalein). Redox reactions are sometimes self- indicating (particularly if it involves the use of potassium permanganate).
After completing the titration, students are often asked to do calculation. To do so, students must be familiar with the topic on mole concept and stoichiometry.
Qualitative Analysis Question in A Level H2 Chemistry Practical
This question involve doing a series of tests on an unknown sample and writing the observations. From the observations, students are expected to predict what’s present in an unknown sample. Reactions involved in qualitative analysis in A Level are usually inorganic reactions, such as testing for cations/ anions. I’ve went through a sample question here and you can watch the video on this here.
However, organic reactions do come out occasionally. Hence, it’s good to revise the organic reactions prior to your A Level Chemistry Practical (just in case…).
Physical Chemistry in A Level H2 Chemistry Practical
There is usually a practical question on physical chemistry – typically reaction kinetics or chemical energetics, although some other topics like equilibrium do come out.
For reaction kinetics, the experiments conducted revolve around tests to determine order of reaction with respect to the reactants.
For chemical energetics, the experiment are usually quite straight forward — adding the reactants together and measuring the temperature change. Once the data is obtained from the experiment, it’s calculation time! Usually the questions will involve finding the heat change , Q using the formula Q = mcΔT. From there, students can find the enthalpy change (ΔH) by taking ΔQ/ n where n is the number of moles.
Sometimes, students are expected to use Hess’ Law to find another enthalpy change of another reaction, so make sure you are familiar with apply Hess’ Law. This can also come out as a planning question.
Within the Scheme of Assessment, Paper 4 is weighted to 20% of the Higher 2 assessment. It is therefore
recommended that the schemes of work include learning opportunities that apportion a commensurate
amount of time for the development and acquisition of practical skills. The guidance for practical work, which
is published separately, will provide examples of appropriate practical activities.
In the planning question, students are often given a set of goals to determine the type of experiment that are needed to achieve the goals. Questions usually guide students by telling them what they need to find. Students would need to write the procedures needed to achieve these aims.
Sometimes, no experiments need to be conducted for the planning question – students just need to write the steps needed, and indicate the data to be collected, and how to use the data collected to determine the goal of the experiment (e.g. purity of a sample, enthalpy change of a reaction and so on).
Quick summary of A Level H2 Practical Exam
If you want a quick summary of what the A Level H2 Practical exam is like, watch this video here.
All the best for your practical exam!