CHEMISTRY COMMUNITY

Hasan Mirza 3F

They will likely give a chart with experimental data which you can use to determine the order.

Hasan Mirza 3F

If I remember correctly, Dr. Lavelle gave a few free points after the 14a final. I could be wrong since it's been a few months.

Hasan Mirza 3F

Before the final do some meditation or some other way to calm yourself cause it'll definitely help!

Hasan Mirza 3F

For me, it depends on how many other campus activities and services are opened up. If it is still very limited then I would probably want to move to an apartment where rent is cheaper than dorm fees.

Hasan Mirza 3F

Yep, keep the anode on the left and remember that the oxidation is occurring there. The right is for the cathode where reduction happens.

Hasan Mirza 3F

I picked up a new book recently called "Anxious People." I haven't finished it yet but the style so far is pretty interesting and it was a bestseller so I think it's worth a read.

Hasan Mirza 3F

Yep! Adding naught signifies that you are talking about standard temperature and pressure.

Hasan Mirza 3F

I've been experiencing a lot of burnout as well, so I appreciate the advice!

Hasan Mirza 3F

If the percent dissociation is less than 5% you can ignore it. You should always double-check.

Hasan Mirza 3F

E naught refers to E under standard conditions of temperature and pressure.

Hasan Mirza 3F

I'm taking BL next quarter along with starting the ls7 series. Not too sure about the difficulty of 14c but I don't think I want to overlap them.

Hasan Mirza 3F

The grading in this class is pretty standard and you only need a 50% to pass. You can check the syllabus for a more detailed breakdown of the points.

Hasan Mirza 3F

The rate of formation is a kinetic factor that controls the potential outcome.

Hasan Mirza 3F

Always put the anode on the left and the cathode on the right.

Hasan Mirza 3F

n in this equation refers to the moles of electrons so just check the balanced equation.

Hasan Mirza 3F

Naught is telling you that the system is at standard conditions of temperature and pressure.

Hasan Mirza 3F

Open systems allow for transfers in matter and energy, closed allow for transfers in only energy, and isolated doesn't allow transfers in either.

Hasan Mirza 3F

Doing as many of the problems from the textbook so that you can be ready for any combination of given information and information you need to solve for.

Hasan Mirza 3F

Larger molecules have more overall configurations which allow for a higher entropy.

Hasan Mirza 3F

Work is definitely dependent on delta V as the equation is: w=P*deltaV

Hasan Mirza 3F

Because the temperature is constant, the reaction will be reversible.

Hasan Mirza 3F

Cp is used with constant pressure and Cv is used with constant volume.

Hasan Mirza 3F

Work being done to a system is positive as energy is being put in, while the system doing work on its surroundings is negative as energy is leaving.

Hasan Mirza 3F

Yes, they always use n for moles so as not to confuse it with m which is for mass.

Hasan Mirza 3F

Try to match the units for pressure, atm or torr, with the ones given in the question.

Hasan Mirza 3F

As long as Pressure and Volume are constant, they are equal because no work is being done.

Hasan Mirza 3F

Cp is specific heat for constant pressure while Cv is for constant volume. Cv + R = Cp

Hasan Mirza 3F

Going off of 14A, I think its safe to say that it will be just the material after MT1.

Hasan Mirza 3F

The bonds being formed release more heat than the bonds broken, but more generally think of a fire. As a fire burns heat is released into the surroundings and is obviously exothermic. Heat isn't a reactant, it is a product.

Hasan Mirza 3F

Always check the pressure units and use the corresponding R value.

Hasan Mirza 3F

Remember the 3 phases are: gas, liquid, solid.
When a substance in any one phase changes to any other phase a phase change occurs.

Hasan Mirza 3F

Condensation is a phase change from gas to liquid. Water requires heat input to vaporize so the reverse would release heat. Therefore condensation is exothermic.

Hasan Mirza 3F

The system you were confused about has one mole of solid and one of gas on one side and two mols of gas on the other. The overall amount of gas is increasing in the system and thus does work on the surroundings.

Hasan Mirza 3F

If you recall the graph showing phase changes of water, there is a very long period where the water is absorbing heat without rising in temperature before it vaporizes. When steam comes into contact with skin, all that heat will be absorbed by the skin before that water can begin to lower in temp.

Hasan Mirza 3F

The general rule is 10^-4 or smaller is fair game. But sometimes you need to make sure that the percent produced is less than 5%.

Hasan Mirza 3F

Just check the units and use the corresponding value on the equation sheet!

Hasan Mirza 3F

Closed systems have a fixed amount of matter and allow the transfer of energy as heat. Volume can actually be changed in such a system but it would most likely be as a result of a change by the experimenter such as moving a piston up or down to change volume and pressure.

Hasan Mirza 3F

Use an ICE chart to set up your problem and solve for the concentration of H+ which would be x. Divide the value of x by the original concentration of lactic acid to determine how much of the acid ended up ionizing.

Hasan Mirza 3F

Remember that you can use the Kw=1.0x10^-14 to switch between Ka and Kb as Ka*Kb=Kw

Hasan Mirza 3F

In some of the sapling problems, the difference between the Ka and concentration needs to be more than 1000 which is 10^3 but in some cases it is better to use 10^-4.

Hasan Mirza 3F

Practicing with the textbook problems and going to the zoom resources are good places to start.

Hasan Mirza 3F

Q>K means the reaction will move towards the products. Q<K means the reaction will shift toward the products.

Hasan Mirza 3F

Q moves towards K and when they equal the same thing, the reaction is at equilibrium.

Hasan Mirza 3F

Atm and Torr are both units for pressure that you should know.

Hasan Mirza 3F

8.206 x 10^-2 is pretty standard for the R but it should always be given.

Hasan Mirza 3F

Q is used at any point in time and is not always at equilibrium. K is strictly for when the reaction is at equilibrium. By comparing Q and K (Q>K or Q<K) you can tell where the reaction is at any point in time and which direction it will move towards in order to reach equilibrium.

Hasan Mirza 3F

K is unaffected by any change except for changes in Temp.

Hasan Mirza 3F

To determine if the reaction is homogenous or heterogenous, you should look at all of the compounds present in the reaction including those that won't be included in the calculations for K or Q.

Hasan Mirza 3F

Yes, all three express the same idea.
Its more preferable to say that equilibrium "lies" or "sits" on a side instead of "shifts" because equilibrium won't actually move and its position is entirely based on comparison to other Equilibrium constants.

Hasan Mirza 3F

Pressure * Volume=n(Moles) * R(Gas Constant 8.314 J/mol·K) * Temperature(Kelvin)

Hasan Mirza 3F

As long as the anion is from a strong acid, and the cation is from a strong base, the salt will be neutral.

Hasan Mirza 3F

The negative charge at the end of the compound is referenced by adding the -ate suffix at the end of the transition metal.

Hasan Mirza 3F

C02, which is always present in air and continuously being committed by countless sources, is an acid that can lower the pH of rain and cause acid rain. Other molecules that find their way into the atmosphere, like SO2 from the combustion of coal, has the same effect to even greater extents.

Hasan Mirza 3F

I believe that metal hydroxides are the stronger of the two simply because they are listed in any list of strong bases while metal oxides are never present. The textbook list says to assume that the base is weak if it isn't included on the list so I wouldn't stray from that rule.

Hasan Mirza 3F

Amphoteric substances need to be able to accept and donate protons. A negative charge is a good indicator that a Hydrogen can be accepted, but if the molecule already has a hydrogen then the molecule can also donate a proton. This isn't a rule for all amphoteric substances but it can be helpful.

Hasan Mirza 3F

From what I've read, you are right in thinking that rotation would cause the pi bonds to break. This is because the pi bonds depend on the parallel orientation of the p orbitals and any rotation would result in the orbitals no longer being parallel.

Hasan Mirza 3F

Graphing calculators are my saving grace here, I just save all rounding until the very end.

Hasan Mirza 3F

I've seen a lot of wishful thinking about extra credit for this class but haven't heard about any in previous quarters so I kinda doubt there will be any.

Hasan Mirza 3F

I was trying a few hours ago and the video playback on ccle froze midway through a lecture on my laptop. I switched to a desktop and I almost finished the lecture but it froze and stopped working right at the end. Now I can't access lectures on either. Kinda frustrating that it's been like this for ...

Hasan Mirza 3F

Lewis acids and bases focus on the movement of electrons, while bronsted looks at the movement of protons.

Hasan Mirza 3F

Always keep a periodic table handy. The distance between atoms on the table is the best way to determine differences in electronegativity which helps determine the bond type.

Hasan Mirza 3F

For organic molecules like in #18, the chemical formulas are written to help you know the location of each atom. For problems like #17 just try to fill the octet of each atom and try using double bonds to help.

Hasan Mirza 3F

As a general rule, you can determine which is more electronegative based on the atoms' proximity to the top right corner. In this case, Cl is much closer to the top right and is much more electronegative.

Hasan Mirza 3F

When the bond order is zero, the molecule is too unstable and won't continue to exist.

Hasan Mirza 3F

Intermolecular forces like london dispersion and hydrogen bonding play a big role in boiling and melting points.

Hasan Mirza 3F

The outermost electrons will be the first to go as they are furthest away from the nucleus and experience electron shielding which makes them easier to be separated.

Hasan Mirza 3F

Intermolecular forces such as London forces and hydrogen bonding will require more energy to break bonds and allow boiling to occur.

Hasan Mirza 3F

The difference in electronegativity. If the difference is >2, it is ionic, and if it is <1.5 the bond is covalent.

Hasan Mirza 3F

London forces are always occurring but they aren't as significant on smaller molecules, especially when compared to other intermolecular forces.

Hasan Mirza 3F

Because of the linear structure, the dipoles cancel out and it is nonpolar.

Hasan Mirza 3F

The most stable structure will be the one with the least formal charges, but the location of those charges is also important. It is more stable for the negative formal charges to be on the more electronegative atoms and positive formal charges on the less electronegative atoms. Sapling #5 is a good ...

Hasan Mirza 3F

All molecules experience London Dispersion forces. The sapling problem was probably asking you to choose the most apparent force present.

Hasan Mirza 3F

Thanks for the resources and explanations. I was really confused with oxidation #'s.

Hasan Mirza 3F

Dispersion forces are present between all molecules. The strength of those forces increases with the size of the molecules involved.

Hasan Mirza 3F

The midterm is still during our discussion sections so it's the same amount of time.

Hasan Mirza 3F

Thanks for all the resources! This helped a lot!

Hasan Mirza 3F

I'm not sure about the number of questions, but I think it's safe to assume that it will be worth the same amount of points and that the format (respondus) will be the same as well.

Hasan Mirza 3F

Assuming the atom is neutral, the # of electrons will = the number of protons (given by the atomic number).

Hasan Mirza 3F

Charts like these are a great visual to help learn the trends but you should definitely try to back the visuals up with an understanding of the concepts.

Hasan Mirza 3F

The advice I got from premeds from earlier years was to choose bio or chem to do first along with math and then take the other science after. I guess taking both at the same time is doable, but I don't have the study habits to sustain that level of work so I'm taking bio after I finish chem.

Hasan Mirza 3F

I think you definitely want to have a good idea of the SI units but the weirder conversions are usually on the formula sheet unless we are told otherwise.

Hasan Mirza 3F

How are Copper and Zinc related?

They're CuZn's

Hasan Mirza 3F

Avogadro's' number is the constant number of any type of particle in a mole. For example, when you are given the molar mass of Hydrogen, that is the weight of 6.022x10^23 hydrogen atoms.

Hasan Mirza 3F

I watched a movie with my family! It wasn't horror though lol.

Hasan Mirza 3F

I believe my TA mentioned them being graded by this Friday.

Hasan Mirza 3F

I recently went to my first workshop and it was super helpful. Also, the modules are really useful if you want to zero in on a specific concept that you are unsure about.

Hasan Mirza 3F

In some of Dr. Lavelle's emails, he sends pdf's titled "Constants and Equations" and "Periodic Table" for us to print out so you should definitely find those and have them ready. Also, my TA said that any calculator should be fine.

Hasan Mirza 3F

I found this in a post from Dr. Lavelle: "For midterms and final, joining the Zoom proctoring session using your cell phone is another option. The student needs to make sure they have Zoom set up on their phone with their UCLA account, and the link to the Zoom session. Using your phone seems mo...

Hasan Mirza 3F

I think because the uncertainty is given in terms of the radius it's best to stick with the given values and not solve in terms of the diameter. It might be solvable either way but it seems like it's an unneeded step.

Hasan Mirza 3F

Did they just omit the 1 in 1x10^8 then? I guess that's equivalent but it definitely threw me off.

Hasan Mirza 3F

Are these sapling problems similar to what we might see on the midterm? Or should I focus more on the textbook problems in that regard?

Hasan Mirza 3F

I'm starting to notice that I need a lot more extra practice so I'll check these sessions out. Thanks!

Hasan Mirza 3F

The ν used for frequency is the greek letter "nu" which looks almost identical to a v. I think for the most part problems should be pretty clear on what is being asked for, such as when a wavelength is given.

Hasan Mirza 3F

I was quite confused about this. Thanks!

Hasan Mirza 3F

This whole thread is super helpful, thanks for all the tips! Still trying to adjust to college classes lol.

Hasan Mirza 3F

Hello everyone i was wondering if anyone could help me with molarity because i never really captured it and i feel like im behind on it. Also if anyone whos where to find actual tutors please let me know. Molarity is the molar concentration of a compound, the formula being M=n/v with the variables ...

Hasan Mirza 3F

I can get to the homework problems through CCLE but how do I get to the textbook with the free trial? If you can get onto sapling, the textbook should be available on the far right side when you are on the main class page with the big bold "University of California, Los Angeles - CHEM 14A - Fa...

Hasan Mirza 3F

AP Chem provided partial credit for work that shows the correct concepts and formulas being applied even if answers don't end up being correct. I'm assuming the same thing will happen in the midterms and final to some extent.

Hasan Mirza 3F

Why does combustion always result in H2O and CO2 and not other compounds? From what I understand, in an ideal combustion reaction H20 and CO2 are the only products. An example of different compounds being released is in an incomplete combustion reaction (which occurs due to a poor supply of O2) whe...

Hasan Mirza 3F

You can use the molecular formulas to find the molar mass, but I just searched it up and got molar mass of butanone on the internet. You would only need to know the formulas for the 2-butanone and 3-methyl-3-hexanol since the other product is in excess. To approach the problem, first use the densit...

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