Q. Are we responsible for lecture notes from a substitute instructor?
A. It's not that simple in college. You should always study what is interesting to you.
If none of it is interesting, first ask why, then come to see me. You may be in the
wrong class (curriculum, major, etc.).
Q. Are the exams cumulative?
A. Yes, absolutely. Chemistry builds and builds. It is not a "one module-forget it-next module" type of subject. You should keep working on your cheat sheet.
Q. What is the format of the exams?
A. Most of the in-class exams will be multiple guess--much harder
for me but easier for the TA's. I may try some regular exams if my
graders appear to be very good.
Q. What to concentrate on?
A. Again, this is high school thinking. In college, concentrate on
what interests you and stimulates the ol' gray matter.
The rest takes care of itself.
Q. Book goes over definitions a lot--do we have to memorize that?
A. I don't care too much about such boring details,
believing that day-in, day-out working of problems will crystallize those
definitions much better than actually memorizing the stuff. Our motto: no sponge
learning! There ARE a few details of nomenclature and such that you
might study but, once again, actually using the names in real
problems probably works better.
Q. Can you use the cheat sheet on final?
A. Yes, but it will be smaller (5" x 7", both sides OK). That's why you should keep distilling your cheat sheet down to the bare essence. Commit important parts to memory.
Hello Dr. Russo. I am in your CHEM1001 class. I am a litte bit confused about the concepts of weight and mass.
Supposed I have 130lb "weight" in ordinary sense, in scientific manner, can I say "I weigh 130 Newton"? Also can I say "my mass is 130/9.8 lb"?
Please tell me the answer. I cannot sleep until I know the truth!!!
Thanks
You need to convert your 130 lb to kilograms: 130 lb = 59 kg. THEN you can multiply by 9.8 m/s^2 to get your weight:
w = 578 kg-m/s^2. You can truthfully say you weigh 578 newtons. But everyone will think you're crazy--even in Europe or Asia where the metric system is used, the results of weight measurements are usually quoted as mass. The 9.8 is factored out.
The English system is more complex, as befits a culture known for its excellent sense of whimsy. Its fundamental units are FORCE, length and time--not MASS, length and time. The standard force is the pound, which is the force exerted by Earth's gravity at a particular point somewhere in the Island Empire on a certain standard body--originally probably a rock? Mass in the English system comes in units of "slugs" such that F(in pounds) = mass(in slugs) x acceleration (in ft/s^2). One pound force = 4.45 newtons. Note that 130 x 4.45 = 578.
Hope you sleep well.
Paraphrased question: I thought that […the entropy of the universe went down when ice forms at T less than 0 centigrade ] because when ice dissolves the entropy of the universe go up since the rivers flood and so on.
When ice freezes, its entropy goes down because a nice, neat crystal is formed. But the entropy of the universe goes up--if the temperature is lower than zero centigrade! Entropy production is favored by dumping heat into a cold body. If ice were to freeze at a higher temperature, its entropy would still go down, but the entropy of the universe would then go down also at this higher temperature--so it doesn't happen. Not until the heat that is given off by the formation of the ice can be dissipated in a cold enough body (i.e,. one at zero centigrade) does ice freeze.
The entropy of a given system can go up or down, but the entropy of the universe always goes up for any process that actually occurs.