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Here is a photo taken in Duluth, MN. This is an area full of iron ores – so much so that the land is the color of rust.
You can see evidence of iron by the color of the river and rocks.
Here are the rusty squirrels I mentioned in class. The squirrels have figured out how to blend in with their lovely coats that are a perfect match for iron oxide.
Rusty Squirrels Blend in with Iron Rich Terraine
Taconite is the most common ore in this area.
Because of the holiday Chemistry 201 met only once and spent a fair amount of that first class taking a test. Why? Because in order to be successful in Chemistry 201 it is critical to have a good foundation in Basic Chemistry – names of the elements, basic structure of matter, simple chemical equations, nomenclature of inorganic compounds, the metric system and it is also critical to have a good foundation is basic algebra – rearrange equations of solve for an unknown, carry out conversions, use proportional reasoning. Any student who is not very comfortable with these skills should immediately seek out support and hit the books! (and the Internet – there are so many useful videos, worksheets, explanations)
On Monday we will have our first lab so be sure to download and print it! We’ll be analyzing an unknown white powder – one of several common household white powders: sugar, baking soda, etc.
Having a laboratory notebook is very, very important! Please bring it to every class.
It seems a long way off but now is the time to being to prepare for your new classes. Early preparation can consist of light review, reading and media viewing that is more fun than work, browsing around the Internet following your interests. The idea is to keep your mind active and develop your curiosity. Once the semester begins you will not be able to control the pace of the learning you are expected to achieve – but you can now!
All grades for both Chemistry 201 and Chemistry 203 are posted in Blackboard and have been submitted in PeopleSoft. I will be on campus on Wednesday afternoon if you wish to pick up your lab books. Otherwise I’ll hold on to them until June. Please stop by and collect them. Have a wonderful holiday.
Dear Students,
It is Friday late afternoon and I am still grading lab reports and lab notebooks. It takes time and I ask for your patience. I will keep you posted and let you know when the grades are posted to Blackboard. This will not happen before Monday.
Summer Research Experience for Undergraduates at Northwestern University
The Materials Research Science and Engineering Center (MRSEC) at Northwestern University offers a 9-week, paid summer research experience for undergraduates. The students are paired up with some of the leading research professors in science and engineering fields. Research areas include ceramics, nanocomposites, photonics, nanoparticles, and molecular electronics. While there are many REU programs, the NU-MRSEC stands out in offering students an interdisciplinary research experience. Students currently pursuing an undergraduate degree in science or engineering who are US citizens or permanent residents are eligible. The program dates this year are June 18 to August 17, 2012; Applications are due Feb. 15, 2012. Participants are paid a $4500 stipend and a travel allowance and on-campus housing is provided. For more information,
please visit our website:
http://www.mrsec.northwestern.edu/content/educational_programs/reu.htm
If you have any questions, please contact our program assistant, Nic Tat
at mrc-reu@northwestern.edu, 847-491-3606.
Here is a link to some very good practice problems with answers on the topic of solution concentrations:
http://www.chemteam.info/Solutions/Molality-from-density-and-percent.html
Also I’ve created two handouts which summarize the steps in these conversions:
1. Conversion from molarity to molality
2. Conversion from molality to molarity
Since both classes have exams this week I’ll be available for questions and problem solving practice as follows:
9:00 – 11:00 Monday – focus on Chem 201
11:00 – 12:30 Monday – focus on Chem 203
5:00 – 6:00 Monday – focus on Chem 203
I’ve posted a fourth practice exam under student resources/exams on my website that covers solution concentrations and colligative properties. There is also a key to this exam. Happy studying!
1. Review section 4.2 Concentration Units: ppb, ppm, Molarity.
2. Review section 4.3 Dilutions: M1V1=M2V2
3. Review section 4.4 Electrolytes vs. Non-electrolytes
4. Study Figure 10.2 regarding sizes of ions.
5. Be able to put compounds and molecules in order of increasing intermolecular interactions: ion-ion, ion-dipole, H-bonds, dipole-dipole, dipole-induced dipole, dispersion
6. Related intermolecular forces to physical properties such as mp and bp.
7. Identify all the regions of the phase diagram.
8. Know more ways of expressing solution concentration: molality, percent by mass.
9. Be able to interconvert concentration units.
10. Carry out calucations for all colligative properties: vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.
11. Use the van’t hoff factor correctly.
Solutions problems and collegative properties problems take lots of practice. I will be in my office tomorrow at 9:00 ready to solve problems for whomever arrives!
Determination of Molar Mass by Freezing Point Depression is now available on my website.
This Spring I will be teaching a course for the first time – Physical Science 107. This course is IAI approved as a 3 credit hour General Education science course (no lab). I’ll be presenting the course in four units: Air, Water, Earth and Fire. The course will exam a variety of fascinating and very current issues: Climate Change, Sustainability, Energy, Environmental Concerns – whatever is in the news. The goal of the course will be to develop the scientific literacy of the non-scientist and to allow students to gain an in-depth understanding of complex problems that affect all of us from the perspective of the scientist. I’ll be developing the syllabus and course website over the next few months. Please let others know about this course and let students know that they can email me, jwalker@ccc.edu, with any questions. I’m looking forward to teaching this course and anticipate many interesting demonstrations, lively discussions and fun projects.
All types of problems with PV=nRT and P1V1/T1=P2V2/T2
Problems about gas density and the relationship to molar mass.
Graham’s Law of effusion (relationship with rate of effusion and molar mass)
The general conditions required for ideal gas behavior.
Description of common gases (as listed on worksheet)
Frequency/Wavelength conversions
Identification of areas of the Electromagnetic Spectrum
Relationship between energy and wavelength/frequency
Three main experiments: Photoelectric Effect, Blackbody Radiation and Emission/Absorption Spectra
Quantum numbers and relationship to properties of orbitals (size, shape, orientation in space)
Aufbau principle (1s22s2…)
Lewis dot structures
Periodic Properties: size and ionization energy
VSEPR Theory
Formal Charge
Shape and polarity of molecules
A special thanks to those students who stayed late yesterday to put in some extra time working on chemistry concepts. This opportunity will be repeated November 30th.
Due to a building evacuation (which was necessary according to protocol but which was precipitated by a hoax) we had to cancel our class. I will make the necessary adjustments to the syllabus and post the changes sometime this evening. In the meantime please enjoy your halloween holiday and study for the quiz – which will be given on Wednesday. The building is open now and all classes are proceeding as scheduled.
The quiz on Wednesday will conver periodic trends and Lewis Dot Structures. Know about atomic and ion size trends so that you can put atoms/ions in order by size. Know about ionization energy trends. Know how to write Lewis Dot Structures.
This homework sheet is very important! Be sure to go over it. http://justonly.com/chemistry/chem201/students/handouts/lewis_practice01.pdf
