Search found 20 matches
- Sat Mar 18, 2017 10:22 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: When to multiply delta H, G, S??
- Replies: 1
- Views: 2065
When to multiply delta H, G, S??
Hi, I'm unclear on when we must multiply a given delta H or G or S by a factor (of whatever we multiplied its associated chemical reaction equation with.) For example, when adding equations, if you multiply all moles of the molecules by 2, you must also multiply delta H of the reaction by 2. I just ...
- Sat Mar 18, 2017 9:49 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3008689
Re: Post All Chemistry Jokes Here
snacking on cyclohexanes while watching lavelle's lectures
- Sun Mar 12, 2017 11:41 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3008689
Re: Post All Chemistry Jokes Here
Why can you always count on a chemist?
Because chemists try. (chemistry)
Because chemists try. (chemistry)
- Sun Mar 05, 2017 11:43 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3008689
Re: Post All Chemistry Jokes Here
What's the only thing worse than organic chemistry? GMO chemistry.
- Sat Feb 25, 2017 11:47 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3008689
Re: Post All Chemistry Jokes Here
What's a good way to study for chem tests? Chemistream Lavelle's lectures. (and do hw problems.)
- Mon Feb 20, 2017 12:11 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3008689
Re: Post All Chemistry Jokes Here
Why did the electrode go to jail?
He was charged with a salt and battery.
He was charged with a salt and battery.
- Sun Feb 05, 2017 11:46 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Quiz Prep 1 #9
- Replies: 2
- Views: 704
Re: Quiz Prep 1 #9
I also still don't understand this question, even after other peoples' explanations. I hope that we can ask someone to review it verbally in person.
- Sun Jan 29, 2017 11:36 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Problem 7.15 (fifth edition)
- Replies: 1
- Views: 799
Problem 7.15 (fifth edition)
"Each of the pictures below shows a molecular view of a system undergoing a change at constant temperature. In each case, indicate whether heat is absorbed/given off by the system, whether expansion work is done on or by the system, and predict the signs of q and w for the process." The pi...
- Sun Jan 22, 2017 10:48 pm
- Forum: General Science Questions
- Topic: How does carbonic acid form?
- Replies: 2
- Views: 1980
How does carbonic acid form?
I know it is formed from carbon dioxide dissolving in water: CO2 + H2O -> H2CO3 But I'm curious about what happens on an atomic level, and why. What kinds of bonds form between which atoms, and what attractive forces lead to them sharing electrons? When I search this on google, nobody really goes an...
- Sun Dec 04, 2016 10:17 am
- Forum: Bronsted Acids & Bases
- Topic: Listing acids in order of increasing strength
- Replies: 1
- Views: 1161
Listing acids in order of increasing strength
This number 7B in the 2012 practice final. Between CH3COOH and C(CH3)3COOH, I'm confused. These are oxoacids, so the electronegativity of the withdrawing atoms is the most important here, and I was wondering, why is H more electronegative than a CH3 group? Aren't the C atoms the ones bonded to the r...
- Sun Dec 04, 2016 10:07 am
- Forum: Ionic & Covalent Bonds
- Topic: least covalent character
- Replies: 4
- Views: 1389
Re: least covalent character
Yeah, HCl vs. CF4, I don't know and would really like someone to answer this, please.
- Sun Dec 04, 2016 10:01 am
- Forum: Resonance Structures
- Topic: Do all resonance structures need to be FC=0?
- Replies: 4
- Views: 1206
Do all resonance structures need to be FC=0?
For example, for the SO2 (subscript 2) structure, one structure has an overall FC=0, but two others have an overall charge of FC=-1. Why do we still count these as resonance structures if they are less stable? When drawing a lewis structure, how would I know how many resonance structures there are i...
- Sun Nov 20, 2016 11:55 pm
- Forum: Bronsted Acids & Bases
- Topic: amphoteric [ENDORSED]
- Replies: 2
- Views: 740
Re: amphoteric [ENDORSED]
thank you!!
- Sun Nov 13, 2016 10:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Will changes in temperature/pressure on rxns be on quiz 3
- Replies: 1
- Views: 777
Re: Will changes in temperature/pressure on rxns be on quiz 3
I highly doubt it, as Professor Lavelle tends to keep his word. However I would really like to get a good score on that graded quiz, even though there is some material I don't know, so official confirmation of this question by a TA or mod would be helpful.
- Mon Oct 31, 2016 11:42 pm
- Forum: Trends in The Periodic Table
- Topic: Electron affinity of nitrogen
- Replies: 1
- Views: 743
Electron affinity of nitrogen
Hi, In one of the professor's previous lectures, he pointed out that nitrogen was an anomaly, because each of its p-orbitals has one electron, for nitrogen to be -1, the electron has to be spin paired into an orbital. Thus it is not favorable because there is electron-electron repulsion. Would someb...
- Wed Oct 26, 2016 9:15 pm
- Forum: Trends in The Periodic Table
- Topic: D-block valence electrons? [ENDORSED]
- Replies: 4
- Views: 6505
D-block valence electrons? [ENDORSED]
Hi, I'm looking for clarification on the valence electrons of the first row of the d-block, namely groups 3-12. Do I take the valence electrons as everything after the last noble gas configuration (Argon, in this case) or do I just take the valence electrons as what's in the 3d and 4s shell, or only...
- Sun Oct 23, 2016 11:51 pm
- Forum: Resonance Structures
- Topic: Breaking the Octet Rule
- Replies: 6
- Views: 1948
Re: Breaking the Octet Rule
Thanks, that was succinct and helpful.
- Thu Oct 13, 2016 12:17 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation [ENDORSED]
- Replies: 4
- Views: 1052
Re: Rydberg Equation [ENDORSED]
In regards to the partial credit vs. no credit, I was doing a problem where I first wrote down E=-hR/n^2, then needed to find frequency v, so using Einstein's equation E=hv, I divided everything by h. I then put it into the form of Ef - Ei = change in Energy. Essentially, I derived the Rydberg's for...
- Sun Oct 09, 2016 10:36 pm
- Forum: Photoelectric Effect
- Topic: Question 18 Part B on Photoelectric Post Assessment [ENDORSED]
- Replies: 3
- Views: 884
Re: Question 18 Part B on Photoelectric Post Assessment [ENDORSED]
Thanks, I was wondering that too.
- Sun Oct 02, 2016 11:45 pm
- Forum: Student Social/Study Group
- Topic: CHEM JOKES
- Replies: 29
- Views: 6863
Re: CHEM JOKES
What kind of fish is only made up of two sodium atoms?
2 Na.
2 Na.