Today the class met in the laboratory room (3175), reviewed some problems, took a quiz, and carried out the experiment: Single and Double Displacement Reactions.
Please complete the exercise “How to Describe” and submit, by email or on paper, descriptive paragraphs of two household items. This exercise should be completed by next Wednesday.
Check List:
Have you turned in your Interview yet?
Have you completed homework assignments 1 to 6?
Have you kept up with the Table of Contents in your Laboratory Notebook?
Have your read the first two chapters of your text book?
And one more “heads up” – the laboratory for Monday is from the laboratory textbook. A single copy costs $2.99 from Centage.
Tonight at 7:30 in room 3162 I will provide an opportunity for folks to make up the first laboratory: Mystery White Powder.
Today we continued to study chemical reactions – and looked at two classification schemes. The classification scheme used for Basic Chemistry sorts reactions into Synthesis, Decomposition, Single Replacement, Metathesis (Double Replacement) and Combustion. Our textbook takes a different approach and recognizes Acid-Base reactions, Precipitation reactions and Redox reactions. We will study redox reactions in more detail later in the course.
Helpful facts:
Not all reactions are redox reactions – atoms (at least two) have to undergo changes in oxidation state for a reaction to be classified this way. Having said this – all single replacement reactions are redox reactions. Metals are oxidized to ions, and in the case of chlorine reacting with hydrogen bromide – the chlorine is reduced to chlorine ion (1-).
Metathesis (Double displacement) reactions are NOT redox reactions. Sometimes they are precipitation reactions – if a precipitate is formed. Sometimes they are acid/base reactions and water if formed.
Most decomposition reactions and synthesis reactions will be redox reactions.
We learned about total molecular reactions, total ionic reactions and net ionic reactions. These terms related to the analysis of a precipitation reaction. To correctly predict precipitates you must know the solubility rules (Table 4.1).
A variety of demonstration reactions were carried out today.
95% denatured ethyl alcohol is combusted in a Blaster Ball Canon
3M H2SO4 is added dropwise to pieces of mossy zinc
Barium nitrate is combined with sulfuric acid to produce barium sulfate, an insoluble white precipitate used to coat tissues for diagnostic purposes.
Milk of Magnesia is diluted with water, universal indicator is added to the mixture, 6M HCl is added in small portions and the solid is dissolved as it neutralizes the acid.
Yellow chromate and orange dichromate can be interconverted by adjusting the pH using HCl and NaOH.
Reminder:Quiz tomorrow covers reactions and stoichiometry. There are practice quizzes posted.
>Reminder: Lab tomorrow – please don’t wear sandals. Come prepared.
Chemistry 201 students took their first quiz, covered material in Chapter Five: the mole, grams to moles and moles to grams conversions, percent by mass, empirical formula, balancing equations, and carried out a laboratory on qualitative analysis. It was a very busy day.
Some folks still didn’t have laboratory notebooks. Monday was the last time that any stamps will be given outside the notebook. Notebooks are required everyday – not just for laboratories but also for demonstrations.
Some folks came to laboratory with no evidence of any preparation – i.e. the notebook was blank. This leads to poor laboratory work. Please come prepared. Read laboratory instructions ahead of time – write title, date and materials into the lab notebook and write a brief outline of the procedure.
A series of entertaining lectures and demonstrations about chemistry and about food presented by Professors Charles Abrams and Joy Walker. Each session will include fascinating stories about food and its preparation with emphasis on the chemistry that underlies the way we experience food. Optional tasing opportunities are provided. You will learn actual practical chemical concepts that will change the way you think about food and its preparation. There are seven sessions. Fee $149.
When and Where…
These lectures take place at Truman College, 1145 W. Wilson Ave., Chicago, Illinois 60640 on Wednesday evenings from 6:30 pm to 7:30 pm. Call (773) 907-4440 for more information or to register. You may also email questions to Professor Charles Abrams, cabrams@ccc.edu and Joy Walker jwalker@ccc.edu
The first worksheets have been posted for the one book extra credit project for this summer. Extra credit is used to resolve borderline grades like 89% – and is worth about 1% of the final grade.
Today we focused on a review of Basic Chemistry – we covered the material in Chapter One and Chapter Two. Topics included states of matter (3 common on Earth and one more universally common), physical change vs. chemical change, units conversions: milli, micro, nano, kilo, quantities: mass, volume and length, density (mass/volume), Rutherford’s gold foil experiment, classification of matter: pure substances vs. mixtures, arrangement of the periodic table: alkali metals, alkaline earth metals, halogens, noble gases, metals vs. non-metals, and nomenclature.
Take a look at problems 1.6, 1.78, 2.3, 2.21, 2.153 from the text book.
We completed an activity to improve our skills giving instructions to each other.
Students took the placement assessment – a 50 question math and chemistry test used to determine readiness for this course. Students who score less than 20/50 on this test are strongly recommended to take Basic Chemistry 121. In cases where the student just finished Basic Chemistry – a low score indicates lack of retention of important concepts. The student should consider spending the summer reviewing Basic Chemistry and taking Chemistry 201 in the Fall where the pace of the course is not so fast.
We went over all the first day documents; syllabus, grading policy, course objectives (student learning outcomes) and spent some time looking over the website.
To do tonight: Continue to explore the website and follow the various links to learn what is available to you.
We briefly discussed atomic structure. Remember that Rutherford’s famous gold foil experiment showed that an atom is mostly empty space.
We went over some expectations for the laboratory notebook. Sample notebooks were passed around. This checklist is a good summary what should be included in a laboratory notebook. We performed the laboratory “Mystery White Powder” where students use a variety of tests to match an unknow substance to one of five know white powders: salt, sugar, baking powder, baking soda and potato starch.
The textbook is highly recommended for this course. We will be covering the first two chapters tomorrow so you might want to read them tonight. If you don’t have the textbook you may want to look over Mark Bishop’s website.
