AQA A Level Chemistry復習筆記5.2.5 Finding Activation Energy
Finding Activation Energy
Finding the Activation Energy
- Very often, the Arrhenius Equation is used to calculate the activation energy of a reaction
- Either a question will give sufficient information for the Arrhenius equation to be used, or a graph can be plotted and the calculation done from the plot
Using the equation:
- Remember, it is usually easier to use the version of the Arrhenius equation after natural logs of each side have been taken
Worked Example
Calculate the activation energy of a reaction which takes place at 400 K, where the rate constant of the reaction is 6.25 x 10-4?s-1.
A = 4.6 x 1013?and R = 8.31 J K-1?mol-1.
Answer
Using an Arrhenius plot:
- A graph of ln k against 1/T can be plotted, and then used to calculate Ea
- This gives a line which follows the form y = mx + c
The graph of ln k against 1/T is a straight line with gradient -Ea/R
- From the graph, the equation in the form of y = mx + c is as follows:
Worked Example
Complete the following table, plot a graph of ln k against 1/T and use this to calculate the activation energy, Ea, and the Arrhenius Constant, A, of the reaction.
Answer
Calculate the activation energy, Ea, and the Arrhenius Constant, A, of the reaction:
Exam Tip
You are not required to learn these equations. However, you do need to be able to rearrange them, and knowing them is helpful in understanding the effects of temperature on the rate constant.
轉載自savemyexams
以上就是關于【AQA A Level Chemistry復習筆記5.2.5 Finding Activation Energy】的解答，如需了解學校/賽事/課程動態，可至翰林教育官網獲取更多信息。
往期文章閱讀推薦：
全網破防！ALevel CIE數學M1疑似錯題？經濟P2難度飆升？5月6日大考考情分析必看！
A-Level CIE就大規模泄題發布最嚴處罰！哪些考生必須重考？你的成績怎么辦？
翰林AMC8視頻課重磅上線！
國際競賽真題資源免費領取
