Topic 11: Kinetics

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.

Use —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 to connect the rule to the data and decision in the question.

This matters because —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 determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —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 to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

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.

Use —the half-life of a reaction to connect the rule to the data and decision in the question.

This matters because —the half-life of a reaction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the half-life of a reaction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The half-life of a reaction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

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.

Use —select and justify a suitable experimental technique to obtain rate data for a given reaction to connect the rule to the data and decision in the question.

This matters because —select and justify a suitable experimental technique to obtain rate data for a given reaction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —select and justify a suitable experimental technique to obtain rate data for a given reaction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Select and justify a suitable experimental technique to obtain rate data for a given reaction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

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.

Use —experiments that can be used to investigate reaction rates by: i an initial-rate method, carrying out separate experiments to connect the rule to the data and decision in the question.

This matters because —experiments that can be used to investigate reaction rates by: i an initial-rate method, carrying out separate experiments determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —experiments that can be used to investigate reaction rates by: i an initial-rate method, carrying out separate experiments to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Experiments that can be used to investigate reaction rates by: i an initial-rate method, carrying out separate experiments is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

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.

Use —deduce the order (0, 1 or 2) with respect to a substance in a rate equation to connect the rule to the data and decision in the question.

This matters because —deduce the order (0, 1 or 2) with respect to a substance in a rate equation determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —deduce the order (0, 1 or 2) with respect to a substance in a rate equation to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

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.

Use —how to: i obtain data to calculate the order with respect to the reactants (and the hydrogen ion) in the acid-catalysed to connect the rule to the data and decision in the question.

This matters because —how to: i obtain data to calculate the order with respect to the reactants (and the hydrogen ion) in the acid-catalysed determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —how to: i obtain data to calculate the order with respect to the reactants (and the hydrogen ion) in the acid-catalysed to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —How to: i obtain data to calculate the order with respect to the reactants (and the hydrogen ion) in the acid-catalysed is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to deduce the rate-determining step from a rate equation and vice versa.

Use —deduce the rate-determining step from a rate equation and vice versa to connect the rule to the data and decision in the question.

This matters because —deduce the rate-determining step from a rate equation and vice versa determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —deduce the rate-determining step from a rate equation and vice versa to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

Be able to deduce a reaction mechanism, using knowledge of the rate equation and the stoichiometric equation for a reaction.

Use —deduce a reaction mechanism to connect the rule to the data and decision in the question.

This matters because —deduce a reaction mechanism determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —deduce a reaction mechanism to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Deduce a reaction mechanism is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

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.

Use —knowledge of the rate equations for the hydrolysis of halogenoalkanes can be used to provide evidence for sn1 and sn2 to connect the rule to the data and decision in the question.

This matters because —knowledge of the rate equations for the hydrolysis of halogenoalkanes can be used to provide evidence for sn1 and sn2 determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —knowledge of the rate equations for the hydrolysis of halogenoalkanes can be used to provide evidence for sn1 and sn2 to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

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.

Use —calculations and graphical methods to find the activation energy for a reaction from experimental data the arrhenius to connect the rule to the data and decision in the question.

This matters because —calculations and graphical methods to find the activation energy for a reaction from experimental data the arrhenius determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —calculations and graphical methods to find the activation energy for a reaction from experimental data the arrhenius to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Calculations and graphical methods to find the activation energy for a reaction from experimental data The Arrhenius is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface for the reaction.

Use —the use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface to connect the rule to the data and decision in the question.

This matters because —the use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The use of a solid (heterogeneous) catalyst for industrial reactions, in the gas phase, in terms of providing a surface is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

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).

Use —core practicals 9a and 9b following the rate of the iodine-propanone reaction by a titrimetric method and investigating to connect the rule to the data and decision in the question.

This matters because —core practicals 9a and 9b following the rate of the iodine-propanone reaction by a titrimetric method and investigating determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practicals 9a and 9b following the rate of the iodine-propanone reaction by a titrimetric method and investigating to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICALS 9a and 9b Following the rate of the iodine-propanone reaction by a titrimetric method and investigating is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICAL 10 Finding the activation energy of a reaction.

Use —core practical 10 finding the activation energy of a reaction to connect the rule to the data and decision in the question.

This matters because —core practical 10 finding the activation energy of a reaction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practical 10 finding the activation energy of a reaction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICAL 10 Finding the activation energy of a reaction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.