CHEMISTRY COMMUNITY

Mikka Hoffman 1C

The reactions will form products to restore equilibrium

Mikka Hoffman 1C

Yes, a triprotic acid has 3 protons, or 3 hydrogens

Mikka Hoffman 1C

I know that sig figs were definitely included in the points for some of the questions on the midterm, so i would assume it will be the same on the final although I'm not sure how much they will be worth.

Mikka Hoffman 1C

Here's a link to the final review session information: https://lavelle.chem.ucla.edu/wp-conten ... ns_14B.pdf

Mikka Hoffman 1C

I would expect around 8 questions, but with multiple parts similar to the format of the midterm.

Mikka Hoffman 1C

yes, the final covers everything we've covered in class so chemical equilibrium will definitely show up.

Mikka Hoffman 1C

Q can be calculated at any point in the reaction, whereas K is only calculated at equilibrium

Mikka Hoffman 1C

yes you should probably know it since it was covered in lecture last week.

Mikka Hoffman 1C

n in this equation is the moles of electrons transferred in your balanced redox reaction

Mikka Hoffman 1C

the textbook says that n in this equation is the number of miles of electrons transferred in the reaction.

Mikka Hoffman 1C

According to the textbook, one vertical line represents interface between two phases, two vertical lines represents a salt bridge, and a comma is used to separate species in the same phase.

Mikka Hoffman 1C

One vertical line represents interface between phases while two vertical lines represents a salt bridge.

Mikka Hoffman 1C

Most likely we will get the midterms back this coming week in our discussion sections

Mikka Hoffman 1C

I think Gibbs free energy is fine as long as it's stuff from after the midterm

Mikka Hoffman 1C

Dr. Lavelle's website says "Test 2 covers all topics on Gibbs free energy and electrochemistry up to the Nernst equation"

Mikka Hoffman 1C

I wouldn't expect integrals or derivatives to be on the midterm, I think they were just used to show how certain equations were derived. It can't hurt to review and know them, though.

Mikka Hoffman 1C

Lyndon made one that you can find if you search "hotdog" on chemistry community.

Mikka Hoffman 1C

I'm not 100% sure but I think the constants and formulas page will be the same on the midterm as on the first test. Here's the link to it: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf

Mikka Hoffman 1C

I would definitely do all the homework problems, as well as going over any old tests. The review sessions are helpful, especially going to the ones that are on topics you're having trouble with

Mikka Hoffman 1C

Because it's insulated, there is no energy exchange between the inside and outside of the waterbottle. An isolated system is characterized by there being no matter or energy transfer between the system and the surroundings

Mikka Hoffman 1C

It's open because it can exchange both matter and energy with its surroundings. For example, you can add or take away tea and it can also be cooled or heated.

Mikka Hoffman 1C

You can calculate Q at any point in the reaction and it will tell you if the reaction is at equilibrium and, if not, which direction the reaction will proceed.

Mikka Hoffman 1C

They're not mandatory, but they are very helpful especially when studying for tests or the midterm/final.

Mikka Hoffman 1C

Yes, I think as long as it's from Thermochemistry (outline 3) you're fine.

Mikka Hoffman 1C

Dr. Lavelle's website says "Test 1 covers Equilibrium and Acid & Base Equilibria"

Mikka Hoffman 1C

Removing product as it is formed results in more product yield because the reaction will keep trying to reach equilibrium as product is removed, so the reactants will continue being turned into product.

Mikka Hoffman 1C

the test takes place during your discussion section starting Tuesday of next week. Also, I had Caram last quarter and we had weekly quizzes each worth 5 points total but he would write the number of points each question was worth next to the questions so we knew how much weight each question carrie...

Mikka Hoffman 1C

Q is calculated the same way as K, so you will always have products over reactants

Mikka Hoffman 1C

When you take away some of the product, the reaction is no longer at equilibrium so it will continue reacting in the forward direction, yielding more NH3

Mikka Hoffman 1C

Kp doesn't have units because they cancel out, so I don't think it matters as long as you use the same units throughout your calculations

Mikka Hoffman 1C

I think the coordination number for this is actually 6 because the central platinum atom is bonded to 5 chlorines and 1 ammonia. This would explain why it's octahedral because octahedral is something with 6 regions of electron density.

Mikka Hoffman 1C

Here's a resource I found helpful: https://www.chemguide.co.uk/physical/ac ... ories.html
Basically amphoteric compounds are not necessarily amphiprotic because some Lewis acids and bases can act as both acids and bases but don't necessarily donate/accept hydrogen ions

Mikka Hoffman 1C

zoepamonag4C wrote:Is H2PO4- a polyprotic acid? What makes something polyprotic?

Something is polyprotic if it can donate more than one proton (Hydrogen)

Mikka Hoffman 1C

Lewis acids accept electron pairs and lewis bases are electron donors.

Mikka Hoffman 1C

hemoglobin and chemotherapy drugs are mentioned specifically on the syllabus, so it's probably a good idea to know at least those two examples.

Mikka Hoffman 1C

The final will be cumulative, and i think it will have about equal parts from all parts of the syllabus

Mikka Hoffman 1C

It is a trigonal planar arrangement because there are three regions of electron density, however, it has a bent shape because you only take into account the atoms when naming the shape. I believe the question itself asks for the molecular shape, so bent/angular would be the correct answer. Hope that...

Mikka Hoffman 1C

I think what the textbook means is that all of the bond angles in SOCl2 are identical, so they all have the same bond angle.

Mikka Hoffman 1C

If you're still having trouble with significant figures, this has been a really helpful resource: https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf

Mikka Hoffman 1C

I think we're supposed to turn in homework for this week and next week (so 14 problems total) in discussion the week after thanksgiving

Mikka Hoffman 1C

The website says that test 3 will cover "End of Bonding from 3.12 (6 Ed.) and from 2D (7 Ed.); and all of Molecular Shape and Structure (see Syllabus and Outlines for details)"

Mikka Hoffman 1C

We don't have lecture Wednesday, and we have Thursday and Friday off, but I'm pretty sure that discussions are still happening Monday-Wednesday

Mikka Hoffman 1C

bigger molecules have more electrons, and therefore more electron shielding so the electrons farther from the nucleus are not as tightly held so they are more easily distorted

Mikka Hoffman 1C

Isolelectronic means that two atoms have the same number of valence electrons and the same electron configuration

Mikka Hoffman 1C

I think for this class at least any time we will need to calculate electronegativity differences the values will be provided, we should just know general trends

Mikka Hoffman 1C

Atomic radius increases down a group because shells are added with more electrons, so the size of the atom increases. It decreases down a period, though, because the electrons are attracted to the greater number of protons in the nucleus, pulling the electrons in closer.

Mikka Hoffman 1C

Kinetic energy of the ejected photon is given by 1/2mv^2 and the energy of the photon is given by the equation E=hv

Mikka Hoffman 1C

This is what the syllabus says about grading: "Each test and exam has a total score but is not assigned a grade. Only at the end of the class when the class average score (out of 500 points) is known are final grades assigned. This class does not use a curve. Group learning (Chemistry Community...

Mikka Hoffman 1C

No it should just be stuff covered in the quantum world outline. I think this is a pretty good list of most of the stuff you should know: https://lavelle.chem.ucla.edu/wp-conten ... _World.pdf

Mikka Hoffman 1C

I don't think so. On the practice problems in the textbook, it only asks you to draw the s- p- and d- orbitals, so I assume any test would not ask you to draw the f- orbital either since it's pretty complicated.

Mikka Hoffman 1C

I noticed that one of your conversion factors is 60sec/1hour when it should be 3600sec/1hour. I would try that and see if it gives you the right answer.

Mikka Hoffman 1C

Professor Lavelle stated that only the material covered in lecture up until last Friday (10/19/18) will be on the test. Since we did not cover periodic trends in lecture, it will not be on the test. If you know everything up until multi-electron atoms, which I believe is section 1E in the seventh e...

Mikka Hoffman 1C

If you're still confused on sig fig rules, this is a helpful resource for what Dr. Lavelle expects with significant figures: https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf

Mikka Hoffman 1C

I don't think you have to memorize the entire spectrum but it would probably be a good idea to have a general sense of what the range for each type of radiation is.

Mikka Hoffman 1C

I think you can do problems from quantum world since that's what the test will be on the same day the homework is due.

Mikka Hoffman 1C

I think this is the sheet that we will be given with all the constants and equations: https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf

Mikka Hoffman 1C

The things that have helped me the most are doing lots of problems from the textbook and doing the video modules that Dr. Lavelle has on his website, including the post and pre-assessments. The examples in the textbook are also a great resource if you are still feeling unsure about certain topics.

Mikka Hoffman 1C

Definitely show enough work to get points, or partial credit if you mess up somewhere. Don't worry about being overly thorough though because you do want to make sure that you finish the test in time.

Mikka Hoffman 1C

I would buy a calculator to use on the test because you will need it for calculations like molar mass and dimensional analysis calculations which can be tricky and time consuming to do by hand. Calculators were not provided during my test, but it might be worth it to double check with your TA.

Mikka Hoffman 1C

In combustion reactions, the reactants are always O2 and the hydrocarbon and the products are CO2 and H2O.

Mikka Hoffman 1C

I don't think that each outline corresponds to a week, but either way I think we'll be told when we switch to subject matter from a different outline/section.

Mikka Hoffman 1C

Hi! You don't multiply the subscript because it refers to how many atoms of that element are in the molecule not how many moles of the molecule are necessary in the equation. If you changed the subscript it would consequently change the molecular composition and the molecule would become a different...

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