4. Answer (a), (b), (c) and (d). (a) Briefly, what two key methods are available for determining the rate law of a reaction? 17 marks] (b) What are the units for the rate of reaction? [3 marks] (c) For the reaction A -- products the first order rate constant is 8.205 x 1045-'. Calculate the length of time it takes for (A) to decrease to one eighteenth its original value. [10 marks] (d) The reaction between carbon monoxide and oxygen to form carbon dioxide has an equilibrium constant, K, greater than 1 x 104 dm' mol' at room temperature: 2CO + O2 = 2CO2 Yet it is known that CO does not spontaneously convert into CO2 in the air around us. Can you reconcile these two facts? 15 marks)