Reaction Kinetics structured questions · GCE A-Level H1 Chemistry

Learning objectives

• explain and use the terms: rate of reaction; rate equation; order of reaction; rate constant; half-life of a reaction; activation energy; catalysis
• construct and use rate equations of the form rate = k[A]m[B]n (limited to simple cases of single-step reactions for which m and n are 0, 1 or 2), including: — deducing the order of a reaction by the initial rates method
• construct and use rate equations of the form rate = k[A]m[B]n (limited to simple cases of single-step reactions for which m and n are 0, 1 or 2), including: — justifying, for zero- and first-order reactions, the order of reaction from concentration-time graphs
• construct and use rate equations of the form rate = k[A]m[B]n (limited to simple cases of single-step reactions for which m and n are 0, 1 or 2), including: — calculating an initial rate using concentration data [integrated forms of rate equations are not required]
• show understanding that the half-life of a first-order reaction is independent of concentration
• explain qualitatively, in terms of frequency of collisions, the effect of concentration changes on the rate of a reaction
• show understanding, including reference to the Boltzmann distribution, of what is meant by the term activation energy
• explain qualitatively, in terms of both the Boltzmann distribution and of collision frequency, the effect of temperature change on a rate constant (and hence, on the rate) of a reaction
• — explain that, in the presence of a catalyst, a reaction follows a different pathway, i.e. one of lower activation energy, giving a larger rate constant
• — interpret this catalytic effect in terms of the Boltzmann distribution
• outline the mode of action of heterogeneous catalysis, as exemplified by the catalytic removal of oxides of nitrogen in the exhaust gases from car engines
• describe enzymes as protein molecules that act as biological catalysts with high specificity (in the reactions that they catalyse and in their choice of substrates as exemplified by the lock-and-key model), temperature sensitivity and pH sensitivity [Knowledge of the levels of structure of proteins is not required. Details of the denaturation process will be discussed in 9 (m).]