Reminder:  Design of Internal Assessment is due next Wednesday, when we return from Mid Winter Break!

1. Warmup

2. Work on 5.2 Study Worksheet 5.2 Study Worksheet

-Here is the handout that accompanies the study worksheet answer key is at the end  5.2 Calculating enthalpy changes

 

1. Warm-up questions about 5.1 Warm up 5.1

2.  Exothermic or Endothermic Mini-lab

 

1. Group work- 5.1.  Work through the Study Worksheet:

Electronic Text Chapter 5/15 Chapter 05 text

5.1 Handout (Class Copy):  5.1 Energetics

Answer key to 5.1 Study Worksheet:  5.1 WS KEY

1.  Introduce last Internal Assessment:  IA Rate of Reaction

2.  Go over calculating uncertainties:  Measurement and Uncertainties

*This is a very inclusive PowerPoint (as it is one of Mr. Jansen’s :)), that should be an excellent resource as you work through your Internal Assessment

Errors in Averages-Please read this excerpt from http://www2.nido.cl/~hlovejoy/practicals/error_and_uncertainities.html:

(e) Repeated measurements

Repeated measurements can lead to an average value for a calculated quantity. The final answer could be given to the propagated error of the component values in the average.

For example,

DH_mean = 102 kJ mol^–1 (±10%)

D H_mean = [+100 kJ mol^–1 (±10%) + 110 kJ mol^–1 (±10%) + 108 kJ mol^–1 (±10%)] / 3

This is more appropriate than adding the percent errors to generate 30%, since that would be completely contrary to the purpose of repeating measurements. A more rigorous method for treating repeated measurements is to calculate standard deviations and standard errors (the standard deviation divided by the square root of the number of trials). These statistical techniques are more appropriate to large-scale studies with many calculated results to average. This is not common in IB chemistry and is therefore not a requirement in chemistry internal assessment.

Here is another handout that briefly discusses what you need to be able to do with uncertainties as an HL student :  2 IB Chemistry Errors and Uncertainties

3.  Questions about Titration Lab – due this week (when you can get it to me).  I will be focusing on the Data Collection and Processing Section to give you feedback for your Internal Assessment.  The conclusion= just summarize the process of the titration and explain your results (how we determined how much aspirin was in your solution).

Okay guys.  I had another concerned student contact me about calculating uncertainties, so it sounds like we need to spend a little more time going over these essential skills to the data processing section.  The intent of this lab is to brush up on skills before we complete our last internal assessment, so we will be taking some time Monday to make sure you understand what is expected.  Do your best with this lab, but don’t panic if you aren’t able to complete the uncertainties.

Monday’s plan:  1) go over calculating uncertainties, 2)  review what the data section of the lab report should look like, 3) introduce our last internal assessment.

I received an email regarding clarification of what you need to do for the Titration Lab.  I expect that you have things ready to go on Monday so that we can look at your work and move on.  We have a very limited amount of time to complete a last IA and finish content.

Here is my response to the email, and I hope it helps to clarify what I’m expecting:

You should have been working through answering the “Calculations” problems from the handout. I left my work/reasoning with the substitute to guide you if you were stuck.

I then wanted you to prepare and Data Processing section like you would for an Internal Assessment. Raw Data Section, Processed Data Section (including calculating uncertainties) and a Sample Calculations section for each unique calculation you performed. This will not be graded as an Internal Assessment, its purpose is to give you more practice and feedback on this aspect so you do well on the last Internal Assessment.  It is also a good way to practice some stoichiometry-which always has the potential to make an appearance on tests and quizzes (as it is a fundamental concept in chemistry).  Did you know that I really like stoichiometry?!

We will not be able to spend much time going over this Monday, so the more you can have completed by then the better.  We need to commence with Topic 5/15 and start discussing our last Internal Assessment.

 

Exam Topic D:  Medicines and Drugs

1) Discuss changes this second semester:

-2 weeks to complete test revisions

-There will be more group work, so to help provide “motivation” to keep people on task during the class period, I am planning on adding a “Classwork” component to your grade which will comprise 15% of your overall grade (taken from the exam allocation).

2)  Today work through the D1 – D3 components of the study guide.

IF YOU WILL BE GONE THIS THURSDAY, you will have three times in which you can makeup the exam:  1)  During class Wednesday (you will be sent to another location while everybody else reviews) 2)  After school on Wednesday or 3) Before School on Friday*.  If you choose before school on Friday PLEASE remind me of this Wednesday as I will have a substitute Friday and will only come in in the morning if needed!