Here are the solutions for most of the questions in the practice set… I gotta have some fun with the remaining two.

# Category: CEM131

## Thoughts for Week of April 10th

**CEM131:** We will be finishing up the Gases chapter this week and starting on Solutions. The Hardness of Water lab is this week’s lab fun.

**BIO220:** We will continue with Eukarya pathogens and start Unknowns. I have posted the current grades, please review missing materials.

**BIO161: ** We will finish Protostomes on Tuesday and then the Exam on Thursday. The lab will either be the field hike or dissection, depending on weather.

## Local Science Internship Opportunity

A local company has just posted an internship for this summer. The company is Transpharm, a local concern that deals with drug testing. This looks like an excellent opportunity to get some experience in the field for students thinking of biological sciences in their future.

## Musings for the week of April 3rd

**General Notes:** We are past the last HQV date, so I cannot drop you from the course. However, if you do not participate (as outlined in the syllabus), you will receive a grade of 0.0 (E) for failure to participate if you do not withdraw before the term deadline. Several people have received emails this week alerting them to this eventuality.

**CEM131:** Exam day today, I know, I love it too (come on, only two problems NEED a calculator). Hopefully it wasn’t too traumatic and I plan on getting them graded by Wednesday. Overall the class is going well and we will start Chapter 7 (Gases) on Wednesday. The lab will be Lab 11 (Molar Mass of Butane) on Wednesday.

On the labs last week I gave you a plus/minus error of one on the hydration number for Copper (II) Sulfate. The actual value was five (5) water molecules for each formula unit of Copper (II) Sulfate, so 4-6 were acceptable. Any value above or below that cost you a point (every group was within two), due to sloppy lab technique (resulting in a poor determination).

**BIO220:** Exam Day on Tuesday, I hope you worked through the Genetics problems… well if you didn’t, I’ll know soon enough. We also have lab on Tuesday where we will do the second Gram Stain test and the Second Streak Plate Evaluation. Thursday we will start in Chapter 12, please read through the Fungi section.

I’m finishing up the labs right now, and I must say that I am rather unimpressed with the depth of short answer responses and the quality of mathematical calculations (forgetting to calculate original concentrations from diluted values, medians, etc.). When I ask you to do some research and compare the behavior of three different microbes in a system, “they are different so they respond differently” is a pretty crappy answer.

**BIO161:** You guys don’t have an exam this week, but you do owe me a formal lab. The class will be working on Chapter 34 (Protostomes) this week. You should be at least through the introduction of the chapter by Tuesday. We are on track for the next exam to be on schedule (4/13).

The overall grades have been updated and include all materials to this point (yes, even the lab quiz). Speaking of the lab quiz, the overall median was 17/25 and the high was 22/25, that gave a curve of +2 (took the median to ~74%).

## Week 3/27 – 3/30

**CEM131:** We will be finishing Chapter 6 this week. I am pushing the exam back to Monday (4/3) so that we can spend a little more time on the calculations. For lab we will be doing the Stoichiometry of a Hydrate.

**BIO220:** We will be finishing Chapter 9 and Evolutionary theory on Tuesday and then Chapter 10 on Thursday. I am pushing the test till Tuesday next week (4/4) so that we don’t have to rush tomorrow. For lab we will be collecting the plate data, discussing identifications, and working on the Gram Stain and Streak Competencies. **Assignment 1 for the presentation is due this Tuesday (3/28)**

**BIO161:** We have the exam on Tuesday. The exam will be followed by our first dissection lab and a discussion of the formal lab requirements. Thursday we will start Chapter 33.

## Office Hours 3/22

I will be late to office hours. It is my semiannual rheumatology check up and I won’t be in till probably 11-11:30.

## CEM131 Lab 3/8/17

This week’s lab will be a continuation of the Lab 6 material. This week we will focus on the Covalent Structures.

## CEM131 Issue with Problem

While I am grading the exam I noticed that I didn’t use the final (corrected) form of one problem and left a typo in that makes the problem unsolvable.

42. Iodine-131 is used to image thyroid tissue to determine the presence of thyroid cancer. Iodine-131 degrades through a beta followed by gamma mechanism. Determine the final product that is produced by the decay of iodine-131. If you can make a 2.0 mCi/ml solution of iodine-131 how much would have to be made 72 hours before the test (half-life: 8 hours) to make a solution with an activity of 7.4 x 10^3 Bq/ml for the test?

The last unit should have been in Bq, not Bq/ml. The question makes no sense at the end with the volume in the unit. However, much of the problem is solvable. So for the five points I will divide it as follows. One point for the decay equation. One point for the conversion of mCi/ml to Bq/ml or Bq/ml to mCi/ml. One point for the determination of the number of elapsed half-lives. If you made an effort at those you will get the last two points (even if you lost some in the previous three) for what would have been determining the amount of radiation needed and then the volume of stock needed. However, if you did not attempt the problem, or only trivially addressed it, you will not get the two final points.

My apologies, I pulled up an old draft when I printed it out.

## CEM131 Lab for 2/22

I did not finish the rewrite in time to post it for you guys, so I will provide copies for the class with no points deductions.

## CEM131 Lab Posted

Sorry for the delay, but the lab for CEM131 is posted for this week. We are doing the Radioactivity lab.