Reaction kinetics

Collision Theory, Boltzmann Distribution and CatalysisSign up

understand, in terms of the collision theory, the effect of changes in concentration, temperature, pressure and surface area on the rate of a chemical reaction · understand that reactions take place only when collisions have sufficient energy, known as the activation energy · be able to calculate the rate of a reaction from: (i) the time taken for a reaction, using rate = 1/time; (ii) the gradient of a suitable graph, by drawing a tangent, either for initial rate, or at a time, t · understand qualitatively, in terms of the Maxwell-Boltzmann distribution of molecular energies, how changes in temperature affect the rate of a reaction · understand the role of catalysts in providing alternative reaction routes of lower activation energy · be able to draw the reaction profiles for uncatalysed and catalysed reactions, including the energy level of the intermediate formed with the catalyst · understand the use of catalysts in industry to make processes more sustainable by using less energy and/or higher atom economy · be able to interpret the action of a catalyst in terms of a qualitative understanding of the Maxwell-Boltzmann distribution of molecular energies

Rate Equations, Order and Half-LifeSign up

understand the terms: (i) rate of reaction; (ii) rate equation, rate = k[A]^m[B]^n where m and n are 0, 1 or 2; (iii) order with respect to a substance in a rate equation; (iv) overall order of a reaction; (v) rate constant; (vi) half-life; (vii) rate-determining step; (viii) activation energy; (ix) heterogeneous and homogeneous catalyst · be able to calculate the half-life of a reaction, using data from a suitable graph, and identify a reaction with a constant half-life as being first order

Determining Order from Graphs and DataSign up

be able to select and justify a suitable experimental technique to obtain rate data for a given reaction, including: (i) titration; (ii) colorimetry; (iii) mass change; (iv) volume of gas evolved; (v) other suitable technique(s) for a given reaction · understand experiments that can be used to investigate reaction rates by: (i) an initial-rate method, carrying out separate experiments where different initial concentrations of one reagent are used (a 'clock reaction' is an acceptable approximation of this method); (ii) a continuous monitoring method to generate data to enable concentration-time or volume-time graphs to be plotted · be able to deduce the order (0, 1 or 2) with respect to a substance in a rate equation, using data from: (i) a concentration-time graph; (ii) a rate-concentration graph; (iii) an initial-rate method

Reaction Mechanisms, Rate-Determining Step and CatalysisSign up

understand how to: (i) obtain data to calculate the order with respect to the reactants (and the hydrogen ion) in the acid-catalysed iodination of propanone; (ii) use these data to make predictions about species involved in the rate-determining step; (iii) deduce a possible mechanism for the reaction · be able to deduce the rate-determining step from a rate equation and vice versa · be able to deduce a reaction mechanism, using knowledge of the rate equation and the stoichiometric equation for a reaction · understand that knowledge of the rate equations for the hydrolysis of halogenoalkanes can be used to provide evidence for SN1 and SN2 mechanisms for tertiary and primary halogenoalkane hydrolysis · be able to use calculations and graphical methods to find the activation energy for a reaction from experimental data (the Arrhenius equation will be given if needed) · understand the use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface for the reaction · CORE PRACTICALS 9a and 9b: Following the rate of the iodine-propanone reaction by a titrimetric method and investigating a 'clock reaction' (Harcourt-Esson, iodine clock) · CORE PRACTICAL 10: Finding the activation energy of a reaction