Rate of reaction study guide

Rate of reaction revision guide ## What this topic is testing Rate of reaction in AQA GCSE Chemistry 8462 asks students to connect definitions, observations, calculations, graphs, and explanations. The important habit is to separate rate of reaction from equilibrium position, and to separate collision-frequency ideas from energy and Le Chatelier explanations. ### Calculating rates of reactions: objective 1 Students should define rate of reaction as the speed at which reactants are used up or products are formed. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 2 Students should interpret rate data from tables and graphs. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 3 Students should use units such as g, c or mol/s for rate of reaction calculations. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 4 Students should compare rates of reaction using graph gradients. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 5 Students should describe why the rate usually decreases as a reaction proceeds. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 6 Students should calculate rate from changes in mass or gas volume over time. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 7 Students should link a steeper graph gradient to a faster reaction rate. In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 8 Students should calculate mean rate of reaction using quantity of reactant used divided by time taken. (MS 1a). In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 9 Students should calculate mean rate of reaction using quantity of product formed divided by time taken. (MS 1a). In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Calculating rates of reactions: objective 10 Students should draw and use tangents to estimate rate of reaction at a specific time from a curve. (MS 3b, MS 3c). In Calculating rates of reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 11 Students should explain that increasing concentration usually increases reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 12 Students should explain that increasing temperature usually increases reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 13 Students should state that catalysts affect reaction rate without being used up. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 14 Students should state that concentration of solutions affects reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 15 Students should explain that increasing gas pressure usually increases reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 16 Students should state that surface area of solid reactants affects reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 17 Students should explain that increasing surface area usually increases reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 18 Students should describe the reaction between sodium thiosulfate solution and hydrochloric acid as a practical method for investigating rate. (AT 1, AT 3, AT 5, AT 6). In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 19 Students should describe collecting gas or measuring mass loss as practical methods for investigating reaction rate. (AT 1, AT 3, AT 5, AT 6). In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 20 Students should use rate data to identify the effect of changing concentration, pressure, surface area, temperature or catalyst. (WS 2.2). In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 21 Students should state that pressure of reacting gases affects reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 22 Students should state that temperature affects reaction rate. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 23 Students should describe methods for investigating factors that affect reaction rate. (AT 1, AT 3, AT 5, AT 6). In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Factors which affect rates of chemical reactions: objective 24 Students should control variables when comparing reaction rates in practical work. In Factors which affect rates of chemical reactions, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Collision theory and activation energy: objective 25 Students should explain that increasing temperature increases particle speed. In Collision theory and activation energy, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Collision theory and activation energy: objective 26 Students should distinguish collision frequency from collision energy when explaining rate changes. In Collision theory and activation energy, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Collision theory and activation energy: objective 27 Students should explain that only collisions with sufficient energy lead to reaction. In Collision theory and activation energy, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ### Collision theory and activation energy: objective 28 Students should define activation energy as the minimum energy needed for particles to react. In Collision theory and activation energy, this belongs to Rate of reaction, so answers should use the exact rate, equilibrium, catalyst, reversible reaction, or graph language from the specification. A strong revision response explains the cause, the observation, and the exam consequence rather than giving a vague keyword. ## Exam technique Use the command word first, then identify the chemistry idea being tested. For rate questions, state what is changing, give the correct unit, and explain graph gradients carefully. For reversible reactions and equilibrium, state the direction of change and explain why the system responds that way. Avoid mixing up faster reaction rate with greater product yield. ## Common checks Check units, signs, axes, and whether the question asks for a rate calculation, a graph interpretation, or an equilibrium prediction. If a catalyst is mentioned, remember that it changes rate but not the final equilibrium position. If pressure, temperature, or concentration changes are mentioned, decide whether the question is about collision theory or Le Chatelier's principle before answering.