CHEMISTRY COMMUNITY

Jocelyne Milke 1G

LG2019 wrote:So all liquids aren't included in the cell diagram or just H2O?

H2O is not included in the cell diagram

Jocelyne Milke 1G

Since isochoric systems are at constant volume there is no work being done so internal energy (delta U) is equal to q. Adiabatic means there is no heat and internal energy is equal to w.

Jocelyne Milke 1G

I think Nathan posted one too and Karen posts hers from her step up sessions!

Jocelyne Milke 1G

going to a few review sessions may help!

Jocelyne Milke 1G

A catalyst speeds up the reaction but does not get consumed in the reaction and doesn't change the rate constant.

Jocelyne Milke 1G

Hadji Yono-Cruz 2L wrote:
Alyssa Wilson 2A wrote:I believe one of the TA's will be holding a review session next week where they will be going through the entire test.

Where and when is this review session being held?

It's held March 12 from 11-12 in Haines 39

Jocelyne Milke 1G

The final review sessions are posted on his website under "Important Final Exam Information". First one starts tomorrow

Jocelyne Milke 1G

You can look at the units for k if it is given or the rate law

Jocelyne Milke 1G

Jchellis 1I wrote:Are significant figures something we are being graded on right now? It seems like he had been pretty relaxed about them recently.

I think it depends on the problem. Some problems he didn't look at sig figs

Jocelyne Milke 1G

Karen's sessions are helpful too! She goes over concepts and has a worksheet

Jocelyne Milke 1G

It shows the relationship between concentrations and the rate of the reaction

Jocelyne Milke 1G

Also for cell diagrams salt bridges are represented by || (two lines) while Porous discs are represented by | (one line)

Jocelyne Milke 1G

Adding water balances the oxygens and H+ balances the hydrogens

Jocelyne Milke 1G

Platinum is the electrode and doesn't participate in the chemical reaction

Jocelyne Milke 1G

I don't think the Nernst equation is included on Test 2

Jocelyne Milke 1G

Here's a picture that may help.

Jocelyne Milke 1G

Gases have more entropy than liquids and solids. Liquids have more entropy than solids.

Jocelyne Milke 1G

I think they accepted either one

Jocelyne Milke 1G

Here's a picture that might help. They both allow for electron transfer

Jocelyne Milke 1G

you can find the oxidation numbers using the periodic table

Jocelyne Milke 1G

Is it because you have to find Q in order to tell if the reaction is in equilibrium or not?

Jocelyne Milke 1G

I think he will post the solutions after the session but they probably won't be detailed so I would recommend going to the review session if you can

Jocelyne Milke 1G

Does anyone have the notes from her last session (feb. 3) that they could email me?

Jocelyne Milke 1G

Gibbs free energy won't be on the midterm. Everything we learned up until the part about entropy we discussed today will be

Jocelyne Milke 1G

The Cv and Cp constants are given on the constant and equations sheet too

Jocelyne Milke 1G

The element is already in its most stable form so the standard enthalpy of formation is zero

Jocelyne Milke 1G

Samantha Silva 1F wrote:Will the TA’s hold a separate review?

I think it depends on the TA but some of the UA's hold review sessions

Jocelyne Milke 1G

Natalie Liu 4I wrote:yes! Thank you so much!

Here you go!

Jocelyne Milke 1G

You can only cancel things out when you have the same compound on the reactants side and the products side.

Jocelyne Milke 1G

I think it also depends on what information is given in the problem so one method might be easier to use for a specific problem.

Jocelyne Milke 1G

Natalie Liu 4I wrote:Hi,
Does anyone have notes from last Friday's lecture?

I have the notes, do you still need them?

Jocelyne Milke 1G

Amy Dinh 1A wrote:On #4a Worksheet 2, I keep getting pH=4.40, while the answer key says 4.30, when both using the quadratic formula and the shortcut way. I don't understand how to get the answer to

in the session she said the pH was 4.40 so you are correct.

Jocelyne Milke 1G

also sig figs for pH count after the decimal.

Jocelyne Milke 1G

I was wondering how many questions test one has? I was also wondering how many points will be taken off for simple mistakes (sig figs, units, etc.)? When will the test take place? Does it cover both equilibrium and acids and bases? It takes place in your discussion section next week and both equili...

Jocelyne Milke 1G

You don't include liquids in your equilibrium expressions because they occur in such large amounts that they are considered the solvents of the chemical reaction. Any reaction that occurs using a liquid will not provide a large enough change to that liquids concentration so as to require us to incl...

Jocelyne Milke 1G

You can memorize the strong acids and bases. Strong acids and bases are completely dissociated. If there is a small Kb or Ka value then it is probably a weak acid or base.

Jocelyne Milke 1G

Homework is due in discussion for the rest of the quarter

Jocelyne Milke 1G

LeannaPhan14BDis1D wrote:K is a constant but it is supposed to stay the same regardless of the different P/R right?

Yes! I believe changing the concentrations of the reactants or products does not change K

Jocelyne Milke 1G

I'm not sure about the second part but the first part is correct. In my notes I also have that if the electronegativity difference is greater than 2 it is ionic and if it is less than 1.5 it is covalent.

Jocelyne Milke 1G

O shouldn't have a +1 since it is more electronegative than Cl

Jocelyne Milke 1G

I think he would clarify which one he wants us to answer but we most likely will be doing molecular geometry

Jocelyne Milke 1G

Ricky Ma DIS 4I wrote:What does polydentate mean and how do I know which ligands can be polydentate?

Polydentate means that the ligand has more than one atom bonded to it.

Jocelyne Milke 1G

The more electronegative an atom, the more willing it is to hold onto the electrons left over when the Hydrogen leaves the molecule.

Jocelyne Milke 1G

Some of them include BeO, Al2O3, Ga2O3, SnO2 & PbO2. They have characteristics in between metal oxides and nonmetal oxides

Jocelyne Milke 1G

to add on, you're combining 1 s orbital with 3 p orbitals

Jocelyne Milke 1G

You can check which posts you've commented on by clicking on "quick links" in the upper left and clicking "your posts"

Jocelyne Milke 1G

His announcement says that the end of bonding and all of molecular shapes will be on test 3

Jocelyne Milke 1G

So we are not taking into account the spin of the electrons? I thought that the energy of an electron did not change if the electron had spin up or down. So for a 4p orbital, would we not have: n=4, l=1, m_l=1,0,-1 and m_s = +1/2,-1/2; a total degeneracy of 6? This would be the total number of elec...

Jocelyne Milke 1G

I think there's 11 total (page 109 in the 6th edition) that we have to know along with the bond angles.

Jocelyne Milke 1G

LorenzoDuvergne3I wrote:Where in the textbook did you find information about sigma and pi bonds? I don't think we've covered them in lecture yet

Sigma and Pi bonds are talked about on page 120 of the 6th edition. (Chapter 4)

Jocelyne Milke 1G

405021651 wrote:Someone on a different post mentioned that it was on the week of November 19th and week 9 which is not making any sense now.

He moved it to week 9 starting Tuesday, November 27. The test schedule can be found on his website

Jocelyne Milke 1G

I think it is stronger than other intermolecular forces but weak when compared to covalent and ionic bonds

Jocelyne Milke 1G

I think we also need to know the bond angles associated with the molecular shapes

Jocelyne Milke 1G

Other molecular shapes are shown in Figure 4.1 on page 109 (6th edition) and they include the bond angles.

Jocelyne Milke 1G

Polarizability is how easily electrons are distorted. Bigger molecules have higher polarizability because there are more electrons and they are more easily distorted.

Jocelyne Milke 1G

Joussie Camacho 4I wrote:Has the key been posted for midterm review worksheet #5?

I think it will be posted after the session ends. (It ends at 6)

Jocelyne Milke 1G

I think you would still have discussion section since we only get Thursday and Friday off for Thanksgiving and your discussion is on Tuesday but it might depend on your TA.

Jocelyne Milke 1G

I think you put them on both cations and anions

Jocelyne Milke 1G

You use the equation FC= V-(L+S/2), where FC is the formal charge, V is the number of valence electrons, L is the number of lone pairs, and S is the number of shared electrons.

Jocelyne Milke 1G

The work function is the energy needed to remove an electron.

Jocelyne Milke 1G

With n=2 you could have l= 0 or 1. If your l=0, then your ml can only=0 (this is one orbital). Since l can also equal 1, your ml can be -1,0,+1. This corresponds to 3 more orbitals so the total number of orbitals would be 4.

Jocelyne Milke 1G

Can someone explain what the statement in #9 of worksheet 3 means? "It is impossible to determine both the speed and position of an electron with absolute uncertainty." Why is it absolute uncertainty and not absolute certainty? It should be with absolute certainty. She corrected the mista...

Jocelyne Milke 1G

yast_27 wrote:Hi!

I was wondering if we should sign up for the peer session as i wanted to attend you session tomorrow,

Thank you very much!

I don’t think you need to sign up, I think you can just show up

Jocelyne Milke 1G

Constants are also given on the sheet

Jocelyne Milke 1G

The constants will be given on the test. You could find the equations and constants given on his website under "Constants and Equations"

Jocelyne Milke 1G

505130452 wrote:For the homework, is there homework due when we have tests, or do we turn it in on Friday or the following discussion?

I think you still turn in the homework for the week in your discussion

Jocelyne Milke 1G

I think you should remember that the wavelength for visible light is between 400 and 700 nanometers and probably know which ones have short wavelengths (like gamma or x rays) and which ones have long wavelengths (like radio or microwaves)

Jocelyne Milke 1G

I heard of a rule about keeping different numbers of sig figs depends on doing multiplication or addition. Does someone know about this rule and maybe help me clarify it? Thank you! For addition/subtraction your answer has to be the same as the smallest number of decimal places from the data and wi...

Jocelyne Milke 1G

Emma Randolph 3D wrote:How many points will the test be out of?

The syllabus says each test will be worth 40 points.

Jocelyne Milke 1G

They are on the syllabus and also on the 2nd lecture outline on his website

Jocelyne Milke 1G

Bianca Barcelo 1G wrote:For these types of values involving leading zeros behind a decimal, (e.g., .041), would you disregard the 0 as a significant figure?

I believe for the example of 0.041 there would be 2 sig figs so the 0 is not a sig fig

Jocelyne Milke 1G

somebody else asked this today in my discussion, the TA said you usually put something into scientific notation if the number is 10^-2 or smaller, and make sure you put the correct significant figures! The number of sig figs used in the final answer is determined by the smallest number of sig figs ...

Jocelyne Milke 1G

Isabel Nkd 4D wrote:Can you clarify if its 2 points max. per week or 3 points max. ?

Thank you!

I think in lecture he said it would be 3 points per week.

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