OCR GCSE Chemistry Practical Activity Group (PAG) Suggested Activities

The OCR model of practical work for GCSE Chemistry is based on encouraging flexibility and teacher professionalism. The required GCSE Apparatus and Techniques, as defined by the DfE Subject Content, have been divided up into Practical Activity Groups (PAGs), mirroring the successful approach taken with our A-Level Chemistry qualifications. Learners are required to carry out a minimum of eight practicals during their study of GCSE (for single science, 16 for combined science). At least one activity per PAG must be carried out, helpingto ensure variety for the learners, and sufficient activities chosen to ensure full coverage of the requirements. Rather than strictly specifying individual practicals, OCR’s approach is to suggest suitable activities and to then allow teachers and departments to choose the activities that best suit them and their learners.

As part of this, we are suggesting three types of practicals per Chemistry PAG:

  • traditional/bench – commonly used practical activities using standard laboratory equipment available in most schools; mainly from the Royal Society of Chemistry Classic Chemistry Experiments publication and the Royal Society of Chemistry/Nuffield Practical Chemistry project
  • microscale – practicals that use reduced amounts of reagents and smaller and/or simpler equipment – mainly from CLEAPSS publications
  • kitchen-chemistry – practicals that use equipment and reagents generally available in the kitchen; mainly based on ideas from our teaching experience and that of other teachers.

Specific suggested activities for each PAG and type of practical are shown on page 3.

In addition to these suggested activities, many teachers and science departments will have their own practical activities that have been developed over the years, which will be equally valid and can be used to fulfil the requirements. Many publishing companies also produce resources to support the teaching of the sciences that include practical activities – for example the OUP Kerboodle package written for the new OCR specifications.

To further support teachers in their planning, teaching and assessment, we are producing practical activity sheets for each of the suggested activities shown in the table below. These activity sheets will include results from trialling of the activities, a range of analysis, interpretation and evaluation questionsbased on the chemistry involved, mapping to the required Apparatus and Techniques, and links to our Learner Record Sheet.

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The GCSE PAG Tracker helps teachers to track learners’ opportunities with the apparatus and techniques, and to ensure that the practical activities chosen fully cover the requirements.

The first set of OCR PAG activities are now available on the qualification pages under the Practical Activities section (Gateway; Twenty First Century Science).

These activities are:

  • PAG 1.2 Reactivity of metals
  • PAG 2.2 Microscale electrolysis of copper(II) chloride
  • PAG 3.2 Chromatography of leaf chloroplasts
  • PAG 4.1 Extraction of limonene
  • PAG 5.2 The march of the precipitANTs
  • PAG 6.2 The vinegar dilemma
  • PAG 7.1 Prussian blue investigation
  • PAG 8.2 The disappearing cross

Note this set of PAG activities does not fully cover all of the required apparatus and techniques. For full coverage, the followingpracticals are additionally suggested. Practical activity sheets covering these activities are currently in production, and will be available soon. Alternatively, the weblinks below are to suitable Royal Society of Chemistry activities or CLEAPSS activities.

  1. A rate of reaction experiment involving gas collection and heating reagents with a water bath – e.g. the effect of temperature on the rate of reaction between hydrochloric acid and magnesium - LearnChemistry
  2. Synthesis of salt withpurification by crystallisation – e.g. synthesis of copper sulfate – CLEAPSS
  3. Investigating enthalpy changes – e.g. mixing pairs of chemicals and measuring the temperature change - LearnChemistry
  4. Flame test on metal salts – LearnChemistry
  5. Titration of a strong acid and alkali - LearnChemistry

Suggested activities for each Practical Activity group and each type of activity:

PAG / Traditional/bench / Microscale / Kitchen-chemistry
1 – Reactivity trends / Displacement reactions of the halogens
e.g. Practical Chemistry project ‘Reactions of halogens (as aqueous solutions)’ / Reactivity of metals
e.g. CLEAPSS ‘Displacement reactions’ / ‘Rusting’ nails investigation – iron/zinc/copper in different conditions
2 – Electrolysis / Electrolysis of brine, gas test for chlorine and hydrogen.
e.g. Royal Society of Chemistry Classic Chemistry Experiment 82 ‘The electrolysis of solutions’ / Microscale electrolysis of copper chloride.
e.g. CLEAPSS ‘The microelectrolysis of copper(II) chloride solution’
(see also CLEAPSS Lab Handbook Section 11 and PP005 – login required) / Electrolysis of brine with 9V battery – chlorine gas test.
Shot-glass synthesis of CO2 – carbon dioxide gas test.
3 – Separation techniques / Preparation of ammonium sulfate
e.g. Practical Chemistry project ‘Preparing a soluble salt by neutralisation’
(see also CLEAPSS Lab Handbook Section 13 – login required) / Thin layer chromatography
e.g. CLEAPSS ‘Thin layer chromatography (TLC) of leaf chloroplast’
(see also CLEAPSS PS67-14 and PS67-15) / Chromatography of food colouring on coffee filters – different separations with water / rubbing alcohol.
4 – Distillation / Extracting by steam distillation
e.g. Royal Society of Chemistry Chemistry for non-specialists ‘Extracting limonene from oranges by steam distillation’ / Small-scale steam distillation
e.g. CLEAPSS crude oil distillation (see also CLEAPSS L195 section 11) or CLEAPSS PS67-03 ‘Extracting limonene from orange peel’ (login required)
(see also CLEAPSS TL004 – login required) / Steam distillation of lavender with vegetable steamer
5 – Identification of species / Cation/anion/flame tests
e.g. Royal Society of Chemistry Classic Chemistry Experiments 80 ‘Testing salts for anions and cations’ and Royal Society of Chemistry Chemistry for non-specialists ‘Flame tests (the wooden splint method’) / Microscale precipitation
e.g. CLEAPSS – ‘precipitates – what is happening?’
(see also CLEAPSS TL017 – login required) / Distillation of salt water with before and after flame tests
6 – Titration / Titration of HCl/H2SO4 with NaOH
e.g. Practical Chemistry project ‘Titrating sodium hydroxide with hydrochloric acid’ (first stage) or ‘A thermometric titration’
(see also CLEAPSS PP020 – login required) / Microscale titration of carboxylic acids with NaOH
e.g. CLEAPSS ‘Microtitration – the acid content of vinegars’
(see also CLEAPSS PP019 - login required) / Investigating vinegar and baking soda solutions and mixtures with vegetable/fruit pH indicators.
7 – Production of salts / Preparation of (NH4)2SO4
e.g. Classic chemistry experiments #91 ‘Making a fertiliser’ / Production of CuSO4
e.g. CLEAPSS ‘Hydrated copper(II) sulfate prepation – microscale’
(see also CLEAPSS PP027 – login required) / Making soap
e.g. CLEAPSS ‘Soap preparation – the microscale way’
(see also CLEAPSS TL007 – login required)
8 – Measuring rates of reaction / Rate of reaction between Mg & HCl
e.g. Practical Chemistry project ‘The rate of reaction of magnesium with hydrochloric acid’
Reaction energetics
e.g. Practical Chemistry project ‘Exothermic or endothermic’ / Rate of reaction between acid and thiosulfate
e.g. CLEAPSS L195 Safer chemicals, safer reactions
(see also Royal Society of Chemistry Classic Chemistry Experiment 64 ‘The effect of temperature on reaction rate’)
Reaction energetics
e.g. CLEAPSS ‘Heat of reaction: the zinc/copper(II) sulfate(VI) reaction’
(see also CLEAPSS TL003 – login required) / Rate of reaction between indigestion tables and vinegar – effect of surface area
Using home-made overwater collection apparatus (glass olive jar, blutac, straws and an ice-cream tub and a water bottle).

Version 11© OCR 2016