Most of the course homework will be delivered through the OWL system. Any problems with OWL should be reported through OWL, as you’ll get help fastest that way. Most assignments are due at midnight on Thursday or Sunday. There is an automatic 24 hour grace period built into each due date. If you finish a problem in the 24 hours after the due date, it will appear as a “?-” in OWL, but you will receive full credit at the end of the semester. The credit for assignments completed within the grace period will ONLY be given at the END of the semester.
If you need access to a computer, you can do so through the Chemistry Resource Center (CRC), or by using your own computer. Check the links below…
what chapters does exam #2 cover? which lectures starting-ending at what dates?
do we have to know all the different wavelengths in the electromagnetic spectrum for the 2nd exam?
electrons!
😉
What are cathode rays?
Yes, he mentioned that multiple photons could be produced out an excited state. but are you asking whether if from n=1 to n=2 more than 1 photon can be produced or if from n=6 to n=1, 5 photon have to be produced, because from the example in class we were given n=6 to n=1 and by using this equation
( delta E= h c/lamda) he found that from n=6 to n=1 there were only 3 photon produced. from that i gather that it probably isn’t just one photon per excited state. I hope that answers your question.
Great! Thanks for answering!
To answer your question, paramagnetic have one or more unpaired electrons so they have an attrated magneitic filed whereas diamagnetic means there are no unpaired electrons, each one has a repelled pair, so it has a repelled magnetic filed.
The books talks about the difference between paramagnetic and diamagnetic, but i dont like its explanation. Anybody have a concise way of remembering it?
Neha,
I remember him saying that if a photon was falling from higher energy level to a lower energy level then that it:
1) emitting a photon and
2) releasing multiple photons if it is falling to more than one energy level.
i remember the professor talking about this today. Did he say multiple photons could be released when it falls from the excited state or just one?
Z* is definitely described in your book.
What is Z with the little star? and whats the point of it?
Katie,
I’m almost positive all owl’s throughout the course will have a 24 hour grace period
Hunds rule is the rule that defines how electron orbitals are filled. Like in class, they fill orbitals all spinning 1 direction and then proceed to fill the opposite direction.
Hope that helps!
What is Hund’s rule??
will we be given a one day extension on the owls due Sunday the 26th? I know you used to allow that. Thanks
I don’t know what the problem is specifically. But it is helpful to remind you of a few things from the book:
the total number of nodes is equal to n-1. The number of planar nodes is equal to l.
For a 5d orbital, n=5 and l = 2; the total nodes = 4, the planar nodes = 2. So there are 2 non-planar nodes, which we call spherical nodes. I’ll draw some in class today.
And possible qn for a 5d orbital:
n = 5, l = 2, ml = (-2,-1,0,1,2), ms = (+1/2,-1/2)
Hi,
I was just wondering if anyone else was unable to submit their answers to the 5d orbital owl question? I have tried everything from rebooting, to re-logging in, but nothing works. I have one past due owl that won’t work. If anyone else find a solution to the same problem let me know. Otherwise I’ll just bring the problem up in class today.
hi Joseph.
i had the same problem but it worked for me after i refreshed the page so try that.
i also had problems getting the “continue” button to work on a couple of SIMs and they worked after i had signed out n came back into OWL at a different time.
Hello All,
There was a question on the most recent OWL hw that said, “there is an electron in the 5d orbital. List all the possible sets of quantum numbers, n, l, m.” I was wondering if anyone knew how to solve this problem?
Thanks Sam
Professor,
There is something wrong with the 6.5b TUT module. It only allows for one answer in the n and l columns and doesn’t respond to the ml columns when you try to put an answer in.
“Same thing we do everyday – plan to take over the world.”
Pinky and the Brain
Thank you Professor! I finally got it, is their a grace period for the 10/12 owls?
Thanks,
Madeline
Hi Madeline and Danielle,
Okay, I haven’t looked at the specific of the final part of that problem. But here is how I would solve the first part of that problem, and the algebra should be completely transferrable:
Problem: 33.6g piece of Cu at 99.8C is dropped into 150g H2O at 18.5C. What is Tf?
Solution: You need to keep two things in mind. First, the heat lost by copper was gained by water – and the “system” is copper with water. In other words, q(Cu) + q(H2O) = 0. Second, heat = m(DeltaT)(Cp). Second, heat = (mass)(Tf – Ti)(Cp). And copper and water have the same Tf.
So….
(33.6 g)(Tf – 99.8 C)(0.385 J/gC) + (150 g)(Tf – 18.5 C)(4.184 J/gC) = 0
All units cancel out to leave only “J” provided that Tf has units of Celcius.
Just expand the above expression to solve for all values that you can, leaving only the terms with Tf alone (something like:
(33.6)(0.385)Tf +(150)(4.184)Tf – (33.6)(99.8)(0.385) – (150)(18.5)(4.184) = 0
etc…
Professor,
In that problem the last question asks you to factor for T-final, and I’m having some trouble with the algebra of how to solve for T-final, I’m having the same trouble as Danielle.
Thank you,
Madeline
Professor,
I, too, am stuck on the same owl problem that Madeline is on. For me, the hardest part is, in fact, the algebra. And of course, the tutorial of how to solve the algebra part is no help at all. Also, in the tutorial I do not understand where the numbers they used for T-initial came from.
Please help,
Danielle
Hi Madeline,
more information, please!
Prof. Knapp,
I’m having some problems with the 5.2h Thermal Equilibrium Finding Final T, I’m having trouble with the last problem and solving for T final, I was wondering if you could give me any hints. Thanks!
Madeline
hmmm. Heat energy from the bar mostly goes to heat the water. But a small amount of energy could also do work on the water, by causing the water to expand (albeit so slightly that we normally ignore this work).
Hi Professor Knapp, I was working on OWL on the topic “Thermal Energy Transfer” and it asked the question “What process other than warming uses some of the energy lost by the metal bar?” I was wondering where I could get this answer?
Neha,
Professor mentioned a couple of lectures ago that he will change the owl due dates to incorporate the grace period at the end of the semester. We wont see the green checkmarks on past due assignments until after then. Hope this helped!
Danielle
hello mike,
i was wondering when the “grace period” for our owls will show up as complete. i have finished them after the deadline, but they still do not show up as completed. thank you!
hello professor,
i was wondering when the “grace period” for our owls will show up as complete. i have finished them after the deadline, but they still do not show up as completed. thank you!
-neha
when are the prs grades going to be fix in the gradebook?
Thanks!
Did you also know that the ability of hemoglobin to bind O2 depends on the acidity of the blood (which is largely determined by the concentration of bicarbonate ion)?
Random Chem fact #84
Did you know the majority of CO2 gas is transported in the blood in the form of bicarbonate ions. When CO2 rich venous blood returns to the lungs the bicarbonate ions dissociate into CO2 and H2O which is then expired out of the lungs.
Simply Amazing.
Hi Mike,
I’m doing the owls due tonight, but when I get something wrong on a net ionic equation problem set, the page website won’t allow me to shift the page left and right to see the answer at the bottom. I don’t know if anyone is having this problem either, but my computer works fine on any other website.
-Ariana
Hi Neha,
Na has a 1+ charge. CO3 has a 2- charge so you need two Na to balance it. Making it Na2 CO3. I think that should help you a little bit.
hello again professor,
so another problem in owl i encountered with net ionic equations..
sodium carbonate and barium bromide in a reaction.
now i would expect that to be Na(CO3)2+BaBr2 yields NaBr2+Ba(CO3)2
but why is it instead BaBr2 + Na2CO3 yields BaCO3 + 2 NaBr.
i dont understand how to decide when the 2 should be as a subscript of sodium or of carbonate. because some reactions, like with NO3, the subscript is with NO3 and not the cation.
can you explain when i have to differentiate? because i keep doing them wrong in owl and cant understand why or how!
Hi Neha,
yes. If one or more products which result from the reaction of two solutions is a solid, then that solid is called a precipitant. And the reaction is a precipitation
professor knapp,
i am doing owls and the ones on precipitation reactions as practice,
i have a question that asks if a reaction is a precipitation reaction.
reading over my notes, i still dont quite understand exactly how to “define” a precipitation reaction. is it just when the product is a solid?
when are the owl grades going to be fixed?
Sherwood
Hi Caitlyn,
I extended a few modules because I thought that the class might benefit from a little more time.
If you want to finish an OWL after the deadline, you should do it – provided that you complete within 24 hours of the deadline, I will give you full credit (the grace period). But note that this 24 hours won’t be obvious to you until I reset the OWL settings.
Dear Professor Knapp,
I was wondering why not all of the OWL questions have an extension of 24 hours after they are due. I noticed only a few of them were extended.
-Caitlyn Shatford
Hi Laura,
yes. even though there are more OWLs than you can shake a dead mouse at, the amount of required time is fairly moderate. Consequently, I intend to assign 5-6 book problems per chapter – OWL will be the bulk of your problem-solving HW.
Professor Knapp,
I was just wondering if the amount of OWLs that we are being assigned will roughly be the same each time? I finished all of the OWLs that are due for the 20th last night and then noticed that about 30 new ones were assigned for the 24th. I guess my question is, should we expect to see this many every few days for the rest of the semester?
Thank you,
Laura Houde
Hi,
I am also having trouble accesssing OWLT, i have the same problem as the other two students. Is there anything that can be done before the deadline tonight?
Hi Charlie,
Give OWL a try now. It should be fine.
Hi Taylor,
I think that you are set for OWL.
I am having trouble accessing the “OWL” webpage. The login page will not recognise my student ID number.
Professor Knapp,
I would greatly appreciate it if I could register for your class on OWL to keep up with the assignments. Thank you.
-Taylor Feraco