The rate and extent of chemical change Flashcards
Calculate the rate of a chemical reaction over time, using either the quantity of reactant used or the quantity of product formed, measured in g/s, cm3/s or mol/s
Mean rate of reaction = amount of product formed (g/s) ÷ time (cm3/s)
or amount of reactant used ÷ time (cm3/s)
Draw and interpret graphs showing the quantity of product formed or reactant used up against time and use the tangent to the graph as a measure of the rate of reaction
HT ONLY: Calculate the gradient of a tangent to the curve on the graph of the quantity of product formed or reactant used against time and use this as a measure of the rate of reaction
Describe how different factors affect the rate of a chemical reaction, including the concentration, pressure, surface area, temperature and presence of catalysts
Required practical 11: investigate how changes in concentration affect the rates of reactions by a method involving measuring the volume of a gas produced, change in colour or turbidity
Use collision theory to explain changes in the rate of reaction, including discussing activation energy
Describe the role of a catalyst in a chemical reaction and state that enzymes are catalysts in biological systems
Draw and interpret reaction profiles for catalysed reactions
Explain what a reversible reaction is, including how the direction can be changed and represent it using symbols: A + B ⇌ C + D
Explain that, for reversible reactions, if a reaction is endothermic in one direction, it is exothermic in the other direction
Describe the State of dynamic equilibrium of a reaction as the point when the forward and reverse reactions occur at exactly the same rate
HT ONLY: Explain that the position of equilibrium depends on the conditions of the reaction and the equilibrium will change to counteract any changes to conditions
HT ONLY: Explain and predict the effect of a change in concentration of reactants or products, temperature, or pressure of gases on the equilibrium position of a reaction
