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C5 Monitoring and controlling chemical reactions

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do catalysts speed up reactions, and how are reactions controlled in industry?

Catalysts and how they lower the activation energy, enzymes as biological catalysts, the effect of catalysts on reaction profiles, and how conditions are controlled to manage rate and yield.
A focused answer to OCR Gateway GCSE Chemistry A topic C5.2 on catalysts and controlling reactions, covering how catalysts lower the activation energy, enzymes as biological catalysts, the effect of catalysts on reaction profiles, and how conditions are controlled to manage rate and yield.
8 min answer →

How do we measure concentration, and how does a titration find the concentration of an acid or alkali?

Concentration in grams and moles per cubic decimetre, calculating concentration, the method and apparatus of a titration, and calculating an unknown concentration from titration results.
A focused answer to OCR Gateway GCSE Chemistry A topic C5.1 on concentration and titrations, covering concentration in grams and moles per cubic decimetre, the titration method and apparatus, and calculating an unknown concentration from titration results.
10 min answer →

How do we measure the rate of a reaction and read rates from a graph?

Methods for following the rate of a reaction, calculating mean rate from quantity and time, drawing and interpreting rate graphs, and finding the rate at a given moment using a tangent.
A focused answer to OCR Gateway GCSE Chemistry A topic C5.1 on measuring and calculating rates, covering the methods for following a reaction, calculating mean rate from quantity and time, interpreting rate graphs, and finding the rate at a given moment using a tangent.
9 min answer →

What controls how fast a reaction goes, and how does collision theory explain it?

Collision theory, the factors affecting the rate of reaction (concentration, pressure, surface area, temperature and catalysts), and explaining each factor in terms of the frequency and energy of collisions.
A focused answer to OCR Gateway GCSE Chemistry A topic C5 on rates of reaction and collision theory, covering the factors affecting rate (concentration, pressure, surface area, temperature and catalysts) and explaining each in terms of the frequency and energy of particle collisions.
9 min answer →

What is a reversible reaction, and how does an equilibrium respond to changing conditions?

Reversible reactions, dynamic equilibrium in a closed system, the energy changes in the two directions, and Le Chatelier's principle applied to changes in concentration, temperature and pressure.
A focused answer to OCR Gateway GCSE Chemistry A topic C5.2 on reversible reactions and equilibrium, covering reversible reactions, dynamic equilibrium in a closed system, the opposite energy changes in the two directions, and Le Chatelier's principle for changes in concentration, temperature and pressure.
9 min answer →