Week of 9/23

Monday: Today I handed back the test and went over a few of the problems that many of you missed. I will be doing a retake for the formulas and moles parts (question 28-35) sometime early next week.  Today we spent working problems.  Many of you, it seems, have a hard time interpreting the problem so that is something to work on.  We also clarified that the double displacement packet will not be collected, but it is strongly encouraged that you do page 12 at least and read through the rest of it.  I will put problems from page 12 on your test in addition to other double displacement reactions that you have not written before.  You will need to be able to predict the products and determine if a reaction has occurred or not. Here’s the work from today’s problems.

Mass Spec Video if you need it.  And check out all the videos I made for you to help with homework. They are under the tab for Unit 2!

Tuesday: Today we started with a  couple warm-up double displacement problems and then I did a demo of how one might use gravimetric analysis to determine an unknown concentration of something.  Test is move to Thursday. Be ready for lab tomorrow!

Wednesday:  You guys were given the challenge to determine the alkali metal in an unknown alkali metal carbonate using a precipitation reaction.  Everyone was able to figure it out and get your reaction completed and filtered by the end of class.

Thursday: Test day.  Took whole block. Boo.

Friday: Finish write-up for alkali metal lab. This involved weighing precipitate, doing calculations, considering what went wrong and then writing a conclusion.

HW: Review limiting reactant.  See videos under unit 2 or 3.

Week of 9/16

Monday: Test day! Covered basic chem, mole problems, mass spec, chemical formula determination and naming.

Tuesday: Solutions intro.  We started with some mole of ions problems from this worksheet. Then we talked about how dissolving happens, the ambiguity of the physical/chemical change.   We also talked about electrolytes and that molecular compounds make non-electrolytes because they do not dissociate!   No homework – just make sure you can do molarity problems! Here’s the notes from today. Also look at this animation of salt dissolving.

Wednesday: I had lots of stuff planned for Wednesday, but we only managed to talk about and do problems on molarity and dilutions.  This took a bit longer than I thought because we needed to review old stuff in addition to helping you grapple with the situation of multiple solutes.

Thursday: We reviewed naming as it became very clear that many of you are struggling with this.  This led into naming acids and then into acid base reactions, net ionic, complete ionic, etc.  This was a short day – about 20 minutes less than usual.  Handed out acid naming packet.

Homework: Watch Percent yield and double displacement reaction videos

Friday: We went over some solubility rules and then wrote precipitation reactions, including net ionic reactions.  Handed out double displacement packet.  Important points:

  • Balance the ionic compound formulas using charges first! Then balance the equation.  If you find it difficult to balance a reaction it is probably because your formulas are wrong.
  • When showing pictures of a a reaction at the molecular level, make it clear which ions are floating around in solution and which are bonded (forming the precipitate).

By Monday you should have all of the textbook problems done.


Week of 9/9/13

Monday: Today we did the green chemistry lab. Kudos to those of you that did the pre-lab in advance! Next year, I will do this differently. I think I will have a person from each group meet with a person from each other group so that you can talk about and compare what each lab report has in it.  Also, I think it would be good if each person presented the method used to calculate the result before you do the pre-lab.   Generally, each group managed to figure out the pre-lab and get the lab accomplished.  It was a good opportunity to get practice with moles and mole ratios in a challenging context, but we definitely could have gotten more out of this experience.

HW: Finish lab, Review mole problems

Tuesday: We did a quick debrief of the green chemistry lab and then reviewed moles a bit.  Rest of class was spent doing book problems listed on unit outline.

HW: Finish lab, finish book problems, watch videos on empirical formula, molecular formula and combustion analysis here.

Wednesday: I presented the story of unit 1 (what I am trying to accomplish/how it all fits together) to give you and idea of what will be on your test.  Then we went over isotopes/weighted atomic average and mass spectrometry.  We didn’t make it much farther than that so we’ll do the planned virtual lab on Thursday, review on Friday and take a short test on Monday.

HW: finish mass spec packet (pg 5-7)finish lab/ work on textbook problems


Empirical formula Simulation Lab

  1. Virtual Lab
    1. Read the experiment description (scroll down a bit past the theory)
    2. Make a data notebook entry for this.
    3. For procedures: give reference URL and summarize the process
      1. What happens? What is measured?
      2. How is the mass of CO2 used to determine the moles of carbon in the original sample?
      3. How is the mass of water used to determine the moles of H in the original sample?
      4. If you know the mass of the carbon and the mass of the H in the original sample, how do you find the mass and moles of the other element in the compound?
    4. Data Collection: Do one random compound that has 3 elements.  (the random option will allow you to see the formulas to check your work)Data Processing Show calculations for empirical and molecular formula
      1. No qualitative observations, uncertainty or error prop required

Friday: Review


Week of 9/3/13

Tuesday: First day stuff. Went over syllabus. Then tested out iPads doing safety activity on safety page. Need to adjust this activity next year. Kids can’t save work because all questions are required! And a bunch of the questions were cut off.  Homework was to get lab safety contract sign and read some of error packet to review sig figs and uncertainties.

Wednesday: Started with safety stuff. (Here’s the lecture) Went over emergency procedures and some key points from the safety quiz.  The rest of class we worked on the density lab.  Homework is to review matter concepts with comprehension questions and finish density lab.

Thursday: Review everything in chemistry day….here’s a pdf of the notes. I handed out periodic tables, ion sheets and some naming practice.  Homework was to do some textbook problems reviewing things from last year.  Note: if you have trouble with the homework – read the associated section of the chapter! It’s all review!

Friday: Went over some homework problems b/c there were so many questions.  Just a reminder – answers are in the back for most of the problems and if you don’t remember how to do something – READ!  The last 25 minutes or so we worked on the pre-lab for the “Green Chemistry: Determine purity of a mixture” Lab.  I sent you home with  a copy of a lab report to help you with the math.  Do not show the lab report to students not in your groups. When you come to class on Monday have the pre-lab done =)

Other advice – Look ahead to homework for next week (Unit outline). Plan ahead! Maybe even get ahead!