The decomposition of hydrogen peroxide (H2O2) produces water and oxygen in a first-order reaction. The concentration of hydrogen peroxide, 𝐶, at any time, 𝑡, is thus given by: 𝐶 = 𝐶0𝑒 −𝑘𝑡 where: 𝐶 is the concentration of Hydrogen Peroxide in mol L −1 at time 𝑡, 𝐶0 is the initial concentration in mol L −1 , 𝑡 is the time elapsed in s, and 𝑘 is a rate constant in s −1 . In an experiment the concentration is measured to be 0.225 ± 0.005 mol L −1 after 20.0 ± 0.5 s. It is found that 𝐶0 = 0.25 mol L −1 with negligible uncertainty. a) Show that the equation can be linearly transformed into the form 𝑦 = 𝛽̂ 0 + 𝛽̂ 1𝑥 and define 𝑦, 𝛽̂ 0, 𝛽̂ 1, and 𝑥. [4 marks] b) Determine the estimate and uncertainty for the rate constant, 𝑘, and report both to an appropriate number of significant figures. [7 marks] c) A proposal is made to change the measurement devices in order to reduce the uncertainty in the rate constant, 𝑘. It is possible to reduce either the uncertainty in 𝐶0 to ±0.004 mol L −1 or the uncertainty in 𝑡 to ± 0.4 s −1 . Which change should be made? Justify your answer. [2 marks] d) A counter proposal suggests that the error in 𝑘 can be reduced without changing the measurement devices as suggested in part c). Instead, a change to the experimental procedure can be made by reading the concentration, 𝐶, at a time different to 20 s. Is the recommendation valid? If so, should the reading be made earlier or later than 20 s to reduce the uncertainty in k? Justify your answer and clearly state any limitations. (Max 100 words)

Please briefly explain why you feel this question should be reported.

Report

Cancel

Help in this statistics question

in progress 0

Engineering MJ 7 months 2024-12-08T22:16:39+05:00 2024-12-08T22:16:39+05:00 1 Answer 13 views Beginner

0