BRAINCAKEMonitoring and controlling chemical reactions
Revision notes for Monitoring and controlling chemical reactions in OCR Chemistry A (J248). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Concentration in mol/dm3 from mass and volumeThe concentration of a solution tells you how much solute is dissolved in a given volume of solution.
- Carrying out an acid-alkali titrationA titration is a technique for finding exactly how much of one solution reacts with a measured volume of another.
- Titration calculationsIf you know the concentration of one solution, and the volumes of two solutions that react completely together, you can find the concentration of…
- Moles and the volumes of gasesEqual volumes of different gases at the same temperature and pressure contain the same number of molecules.
- Calculating gas volumes in reactionsYou can predict the volume of a gas made in a reaction using the molar gas volume.
- Concentration in g/dm3 from mass and volumeConcentration can also be given as the mass of solute in a volume of solution.
- Calculating the theoretical mass of a productThe theoretical mass of a product is the mass the reaction would make if all of the reactant were converted to product and nothing were lost.
- Calculating percentage yieldThe actual yield is the mass of product you really collect at the end of an experiment.
- Defining atom economyAtom economy is a measure of how much of the starting materials ends up as the desired product.
- Calculating atom economyYou calculate atom economy from the balanced equation, using relative formula masses (Mr).
- Choosing a reaction pathwayA chemical company often has more than one reaction pathway to make the same product.
- Practical methods for finding the rate of a reactionThe rate of a reaction is how quickly reactants are used up or products are formed.
- Interpreting rate of reaction graphsA rate graph usually plots the amount of product, such as the volume of gas, against time.
- Factors that change the rate of a reactionFour changes affect how fast a reaction goes.
- Collision theory and the rate of reactionFor a reaction to happen, particles must collide with enough energy to react.
- Surface area to volume ratio and rateOnly the particles on the surface of a solid can meet the other reactant.
- CatalystsA catalyst is a substance that increases the rate of a reaction without being used up.
- Identifying catalysts in reactionsA catalyst is a substance that makes a reaction go faster but is not used up.
- Catalysts and activation energyParticles only react when they collide with at least a minimum amount of energy, called the activation energy.
- Enzymes as biological catalystsLiving cells carry out thousands of chemical reactions.
- Reversible reactions and altering conditionsMany chemical reactions go only one way, but some are reversible.
- Dynamic equilibriumImagine a reversible reaction in a closed system, where no substances can enter or leave.
- Le Chatelier's principle and equilibrium positionLe Chatelier's principle says that if a change is made to the conditions of a system at equilibrium, the position of equilibrium shifts to oppose…