CHEMISTRY COMMUNITY

Xin Huang 3E

In 2014 final, Q5 (D) has a naming given "prop-2-en-1-ol" as the answer. However, shouldn't the double bond be given the highest priority to have the lowest order of carbon, before all of the other substituents? I got "prop-1-en-3-ol" for this.

Xin Huang 3E

I know that Dr. Lavelle mentioned that in lecture, but I forgot-- Which functional groups are going to be tested on?

Xin Huang 3E

Why would this restrain also resist the rotating from higher energy to lower, namely from eclipses conformation to staggered?

Xin Huang 3E

From previous finals I rarely see proofs. However, the midterm this quarter involves one proof so I cannot be sure. I feel that Dr. Lavelle's exam usually has some problems that test your understanding of certain concept (problems that do not require calculation but more like explanations). So even ...

Xin Huang 3E

On p.93 in the course reader, it says that equivalent H are H with same chemical environment--are there more detailed conditions for equivalent H? It seems that the H should be attached to same amount of same atom...what else? If nothing else, then every H on an alkane should be equivalent H?

Xin Huang 3E

Will the answer key of the quiz 2 practice be posted on chemistry community? Hopefully @Chem_Mod will post it before the quiz ^ ^. Or does anyone want to share her/his answer?

Xin Huang 3E

For half-reactions, when do we leave out the water or other substances, and when do we incorporate them?
E.g. For Q7 in Winter 2013 Midterm, I notice the answer indicates:
2Mn2+(aq)+8H2O(l) --> 2MnO4-(aq)+16H++ 10e- for the anode;
Why don't we write instead: 2Mn2+(aq) --> 2Mn7+(aq)+10e- ?

Xin Huang 3E

For the rate of a reaction, is the order the same as the stoichiometry of a reaction?
E.g. for 2H2 + O2 => 2H2O is the rate equals to k * [H2]^2 * [O2]^2?
(wait I just realized they are gas... well...just suppose they have concentration)

Xin Huang 3E

If entropy is a state function, why is DeltaSurr not equal to zero when DeltaSys is? Because Entropy of surrounding is not a state function as entropy of the system does. And since deltaTotal is always > 0 (since this is the universal trend haha the world is always tending to confusion) while delta...

Xin Huang 3E

I am also wondering about #9, specifically about ΔS(surr), why is it not 0? Isn't it a state function, too? I know that ΔS(sys) + ΔS(surr) = ΔS(univ) > 0, but that is only for a spontaneous process? Why is #9 a spontaneous process?

Xin Huang 3E

Hi, I noticed that on course reader p.33 there are two graphs showing reversible and irreversible pathways. One of them (Path A) has constant temperature, while the other has changing T. But it seems that for both of them ΔU = 0 (since q = -w for both of them). I originally thought that ΔU = 0 for c...

Xin Huang 3E

For the second way of changing the energy of a system, "heat or cool the system", the course reader said only the closed system is eligible. What about open system? Why can't we change the energy of an open system by heating or cooling it?

Xin Huang 3E

I have kept been confused by the different denotation of ΔH, ΔHf, ΔH(RXN), ΔH(NET), ΔHo - (o as superscript)
1. What does RXN stands for? reaction?
2. When we do homework problems or take midterm & final, is it incorrect to write just ΔH instead of those with different denotations?

Xin Huang 3E

I notice that when I buy the course reader there is no longer a quiz practice book along with the course reader... Does that mean that there will no longer be practices for the three quizzes or any "three mock quizzes replacing the lowest quiz score" deal?

Xin Huang 3E

If any one has a hard time with the calculation of pH for Weak Base-Strong Acid Titration or (Weak Acid-Strong Base, which is the vice versa), check out this website: http://chem.libretexts.org/Core/Analytical_Chemistry/Lab_Techniques/Titration/Titration_of_a_Weak_Base_with_a_Strong_Acid This page i...

Xin Huang 3E

I was solving problem 17.35 and I had a sense that only (b) can form a chelate (polydentate) ligand, but I was not completely sure why. And the answer says "Only the molecule (b) can function as a chelating ligand. The MH2 groups in (a) and (c) are arranged so that they would not be able to coo...

Xin Huang 3E

Are we going to the same room as midterm to take our final or are we going to be assigned new rooms?

Xin Huang 3E

Hi, can anyone kindly tell me how to determine the order of ligands when we write the formula for a given name of coordination compounds? I know that the metal should be before all the ligands, but for the ligands, do we write them in random order, or order of their charge, etc.?
Thank you!

Xin Huang 3E

Should we write detailed version of electron configuration like:(σ2s)2(σ*2s)2(π2px)2(π2py)2(σ2pz)1
Or a shorter version like: (σ2s)2(σ*2s)2(π2p)4(σ2p)1
in quiz 3?

Xin Huang 3E

How do we convert the pressure to concentration?

Xin Huang 3E

What should we do if there is a mix of gas and aqueous? do we use Ec or Ep or something else?

Xin Huang 3E

I was wondering what is the trend of electron configuration for weird metals, for example that is, consecutively, Ce is [Xe] 4f1 5d1 6s2, while Pr is 4f3 6s2. There is no half full situation, so why does the electron in 5d goes to 4f while increasing only one electron?

Xin Huang 3E

What should we write the electron configuration with noble gas abbreviation for an ion that has equal electrons in their outer shell with a noble gas? I.e. For Br- should we write [Kr] or [Ar]3d10 4s2 4p6

Xin Huang 3E

On the Course Reader p. 29, it says we write "4s" before "3d" but says that after 4s state occupied and e- enter 3d state then 3d state is lower in energy than 4s. What does that mean... Why is this?

Xin Huang 3E

Is midterm in similar form as the quizzes? (just FRQs and no MCQs) And until which point will it test on...? This Friday...or next Monday...?

Xin Huang 3E

I think the reason why he sounds so mysterious is that he wants to give us a "surprise" through, lol.

Xin Huang 3E

Sounds logical ^ ^. Thank you so much!

Xin Huang 3E

About the rough guideline of differentiating the ionic bond and covalent bond, I am still a little confused about those electronegativity difference falls between 1.5 to 2, how we should figure out what types of bond there are. I was a little off on the class, so...I heard Dr. Lavelle mentioned how ...

Xin Huang 3E

Oh! We will have a mid-term?! I thought we only had Final...Then what is the mid-Term time for those who does not have test conflicts?

Xin Huang 3E

Are quizzes the form similar as self tests or are they in MCQs? And if they are FRQs, are detailed steps required, or only an answer should be OK?

Xin Huang 3E

Heisenberg Uncertainty Principal:
1. C; 2. D; 3. D; 4.B; 5. C;
6. A; 7. D; 8. D; 9. A; 10. D;
11. A; 12. D; 13. A.

Xin Huang 3E

Wave Properties of Electrons and The De Broglie Equation:
1. B; 2. A; 3. CONSTRUCTIVE; 4. CONSTRUCTIVE; 5. DESTRUCTIVE;
6. FALSE; 7. A; 8. D; 9. B; 10. A;
11. A; 12. TRUE; 13. B; 14. C; 15. B;
16. B; 17. A; 18. D; 19. B; 20. A;
21. C; 22. B; 23. A; 24. C; 25. D;
26. B; 27. C.

Xin Huang 3E

Atomic Spectra:
1. A; 2. C; 3. D; 4. C; 5. NO;
6. B; 7. A; 8. D; 9. D; 10. A;
11. D; 12. A; 13. C; 14. A; 15. D;
16. D; 17. D; 18. FALSE; 19. FALSE; 20. TRUE;
21. TRUE; 22. TRUE; 23. D; 24. C; 25. A;
26. D; 27. B; 28. B; 29. D; 30. B.

Xin Huang 3E

I am willing to share my own answers, but due to the fact that I'm so unconfident with the accuracy of these answers, please don't use my answers as model. If you see any incorrect answer, I would be so thankful if you could point out, and I will fix them on these posts. Let's make our "solutio...

Xin Huang 3E

Hi everyone, I wonder if all of you have completed the online assessments for the following modules (We are supposed to finish these before the end of this week right...?) Empirical and Molecular Formulas Balancing Chemical Equations Limiting Reactant Calculations Molarity and Dilution of a Solution...

Xin Huang 3E

Oops, my bad. Thank you for pointing out my flaws

Xin Huang 3E

Yes, I believe you can replace ONE quiz grade with BOTH of the self-quiz on the workbook, but you HAVE to hand them in before each of your real quiz for credits.

Xin Huang 3E

This is Problem #10 on Pre-Module Assessment: According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass of AgCl produced? C6H9Cl3 + 3AgNO3 ---> AgCl + C6H9(NO3)3. Molar Mass: C6H9Cl3...

Xin Huang 3E

I'm sure that those are review problems that Dr. Lavelle wants us to go through our high school materials; therefore, it might not influence the tomorrow lecture I believe... You can complete it at later time. But you'd better complete it sooner the better, cuz in your discussion sessions, your TAs ...

Xin Huang 3E

If you want to get the 6th electronic version of the textbook, plz email me your email at helengracehuang@live.com, so that you can use this book to find the right numbers of problems ^-^

Search found 40 matches