Last week we only had 2 days of school and one of them was short due to a 2 hour delay! Yay for snow days! On Thursday we did went over questions on the practice test and Friday I was out for most of the class so you worked on homework problems or the practice test.
Monday: Today was the acid-base test day.
Homework is to read sections 2.1 to 2.3 and watch the video on atomic emission spectroscopy:
Tuesday: History of atomic structure notes. Here’s some of the videos I used.
Homework: Work on PES (Photoelectron Spectroscopy) packet, check atomic structure/ periodic trends review and let me know if there is anything you don’t know…otherwise – I expect you to know everything on there.
Wednesday: Today we did a bit of review of basics for those of you that needed a refresher and then launched in to the Bohr model lab. The point was to see how we can use the wavelengths given off by hydrogen to determine the energy level transitions that caused them. This evidence supported the idea that electrons exist in energy levels. Today was short b/c of a snow delay so more of the analysis is HW now. Labs will be graded on Monday. Turn them in by beginning of class Monday.
Thursday: Today we went over periodic trends. We started with Coulomb’s law and discussed atomic radius, ionic radius and ionization energy. I had you write answers to certain questions that you’d turn in for feedback. For all but ionic radius, check out videos here for help. HW: finish PES packet and Bohr Model lab.
Friday: Worked on PES packet in group. At the end you all turned one in and I would pick one randomly to grade. HW: rewrite electron affinity trend and do AP practice test problems.
Friday: Indicator lab and math to determine pH range that indicator will change color (pKa + or – 1). Plus showed titration curve for polyprotic acid.
Buffer Lab Due Wednesday
Some homework solutions.
Hw solutions 16.91&16.119
Homework solutions sec try
Week of 1/6
Thursday (1/2): Today was our first day back from break and we started with a Standardization lab. I explained why you need to standardize NaOH solutions and then you guys practiced performing titrations with an indicator, rather than a pH probe as in Ca(OH)2 Ksp lab. Homework was to read the Half titration lab. Oh, I also put the derivation of the Henderson-Hasselbach equation on the board so that you would know where it came from (part of the Half titration lab).
Friday: Snow day.
Monday: Performed the Half-Titration lab and completed analysis. UNIT OUTLINE
Tuesday: Had a 2 hour delay b/c of severe cold. Some kind of polar vortex! We had 30 minutes to learn Salt Hydrolysis. We did a quick lab where you added NH4Cl, NaHCO3 and NaCl to water to see that it changes the pH. The point was for you to see how the pH can change when you put something in it that doesn’t appear to be an acid or base at first. I then explained how this happens. HEre’s the notes. Worksheet. Note to self. Everyone is totally confused by symbols. Maybe skip this until later in the unit next year.
Thursday: We started with a review of salt hydrolysis – determining if a substance will be acidic or basic and how to calculate pH. I don’t have digital copy of worksheet…Sorry, E! You might be able to figure it out from answers that start on page: 8 of the notes. Then I did the buffer demo you can see here (if you scroll down till the picture of 4 beakers w/ green a blue solutions). We went through a pretty simple buffer example and I handed out this worksheet for worked solutions and more practice. Homework was from unit outline. Here’s a video on calculating pH for buffers. There’s more videos on the Unit 7 page on this blog.