Chemistry HL IA – Investigation on the activation energy of decomposition of H2O2

이 IA 는 2022 년에 제출된 HL IA이고 pressure sensor 를 통해 H2O2 decomposition rate 를 구하고, 이를 통해 H2O2 decomposition activation energy 를 구했습니다. Uncertainty calculation, 그리고 pressure change 를 통해 reaction rate 를 구하는 계산과정 등 계산과정이 자세하게 나와있습니다. 최종점수로는 22/24점을 받았습니다. Chemistry IA 에서 7점을 받기위한 요소들을 참고하는데에 도움이 될것으로 예상됩니다.

[본문내용]

Investigation on the activation energy of decomposition of H2O2

Research question

What is the activation energy of the decomposition of 0.25M H2O2
in the presence of MnO2, determined by calculating the instantaneous rate of reaction at different temperatures (30 ˚C, 35 ˚C, 40˚C, 45˚C, 50˚C) using a gas pressure sensor?

Introduction

In 10th grade chemistry class, I conducted an experiment that investigated the rate of reaction between magnesium and HCl. Back then, I used a methodology widely available in textbooks: collecting the gas inside the gas syringe, and calculating the average rate of reaction. However, I noticed that the observed data was highly inaccurate due to the stiffness of the gas syringe that does not expand correspondingly to the increase in no. of gaseous molecules. Instead, the gas syringe will intermittently expand, giving inaccurate data. Also, the calculation of the “average rate of reaction” was not accurate enough to reach a meaningful conclusion. I personally wanted to investigate a better methodology that could accurately measure the rate of reaction while avoiding the use of gas syringes or the “average rate of reaction”. To do so, I devised a new equation that allows the calculation of the
instantaneous rate of reaction using a gas pressure sensor.
For this investigation, the chosen reaction is the decomposition of hydrogen peroxide, catalyzed by manganese [IV] oxide. The reason for this choice is that the reactants are readily available in labs, and the fast reaction allows the collection of a sufficient number of data within a limited amount of time. The aim of this experiment is to calculate the activation energy of the chosen reaction, by measuring the instantaneous rate of reaction at different temperatures. This will be used to answer the research question, which is to determine the activation energy of decomposition of H2O2 under MnO2. Additionally, the experimental value will be compared to the literature value of the reaction, which is around 50kJ/mol, to test the accuracy of the devised equation (Jildeh, 4)…

• 총 페이지수: 13 pages
• 과목명: Chemistry
• 주제: Investigation on the activation energy of decomposition of H2O2
• The file is in PDF format.