RI Kinetics Remedial

Name: ………………………………………. ( ) Class: ……………. Date: ……………. Raffles Institution Year 6 H2 Chemistry 2025 Set A T2W3 – Kinetics Notes: overall order of reaction rate equation units of k rate- [reactant] graph [reactant]- time graph half-life (circle) zero rate = k constant / not constant one rate = k[A] constant / not constant two rate = k[A]2 constant / not constant rate [A]0 [A] time0 rate [A]0 [A] time0 rate [A]0 [A] time0  Pre-ChemFocus Activity  • Revise key concepts in Kinetics: half-life, “clock” and continuous experiments. • To view infopack at IVY > C2025 – H2 CHEMISTRY > Pages > [ChemFocus] Y6 T2W3 Kinetics (and Y5 T3W9, if needed) > FIRST VIDEO ONLY

Self-Check Questions 1 The diagram shows the energy profile of a reaction that occurs with and without a catalyst. Which of the following can be deduced from the diagram? A E4 is the . B The forward catalysed reaction is endothermic. C The enthalpy change of reaction is (E2 – E3). D The enthalpy change of reaction is decreased by using a catalyst. 2 Which changes would cause both of the rate constants k1 and k–1 to be increased? 1 introducing a catalyst 2 heating the equilibrium mixture 3 increasing the concentrations of the reactants A 1 , 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only Check your answers at IVY > C2025 – H2 CHEMISTRY > Pages > [ChemFocus] Y6 T2W3 Kinetics > Remaining videos

3 A chemical plant illegally dumped some radioactive waste in a landfill. This waste contains two radioactive isotopes M and N. The half-life of M is 3 days whereas that of N is 2 days. The authorities found out about this illegal dumping only when the waste had been in the landfill for 12 days. They did an immediate analysis on a sample of the waste and found equal amounts of M and N. Considering that the decay of radioactive isotopes follows first-order kinetics, what is the molar ratio of M to N if the waste had been in the landfill for 6 days? M : N A 1 : 4 B 1 : 2 C 2 : 1 D 4 : 1 4 The reaction between potassium manganate(VII) and ethanedioic acid is an example of auto-catalytic reactions, in which one of the products catalyses the reaction. 2MnO4–(aq) + 5H2C2O4(aq) + 6H3O+(aq) → 2Mn2+(aq) + 10CO2(g) + 14H2O(l) Which graph correctly represents the kinetics of this reaction?

Tutorial Discussion Questions (to complete before Chemfocus session) 1a [modified NYJC 2018/I/9] The decomposition of hydrogen peroxide follows first order kinetics. 2H2O2 ⟶ 2H2O + O2 A certain solution of hydrogen peroxide undergoes complete decomposition to liberate 96 cm3 of oxygen gas. It is found that at 20 °C, 48 cm3 of oxygen was collected in 35 min. Use the following equation, how long will it take for 80 cm3 of the gas to be produced? (H2