BRAINCAKEMonitoring and controlling chemical reactions
Revision notes for Monitoring and controlling chemical reactions in OCR Combined Science A (J250). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Practical methods for finding the rate of a reactionThe rate of reaction is how fast reactants are used up or products are made.
- Interpreting rate of reaction graphsA common graph plots the volume of gas made (or the mass of product) against time.
- Factors that change the rate of reactionFour things change the rate of a reaction.
- Collision theory: temperature, concentration and pressureFor particles to react they must collide, and they must collide with enough energy.
- Surface area to volume ratio and rateOnly the particles on the outside of a solid can meet the other reactant.
- Characteristics of catalystsA catalyst increases the rate of a reaction without being used up.
- Identifying catalystsA catalyst is a substance that speeds up a chemical reaction.
- Catalysts and activation energyFor particles to react they must collide, and the collision must have enough energy.
- Enzymes as catalystsLiving things carry out thousands of chemical reactions in their cells.
- Reversible reactionsIn most reactions the reactants turn into products and that is the end of it.
- Dynamic equilibriumA reversible reaction in a closed system, where nothing can enter or leave, eventually reaches dynamic equilibrium.
- Changing the position of equilibriumLe Chatelier's principle says that if you change a condition of a system at equilibrium, the position of equilibrium shifts to oppose the change.