CHEMISTRY COMMUNITY

Naomi Hernandez-Ramirez 1J

salt increases water's ability to carry a current at the surface of a metal hence increase rusting

Naomi Hernandez-Ramirez 1J

unbalanced equation is:
Fe + H2O + O2 -> Fe2O3∙3H2O
----coefficients are missing

Naomi Hernandez-Ramirez 1J

pH measures the concentration of H+ ions in a solution, through this we can know where it lands on the scale of 1-14

Naomi Hernandez-Ramirez 1J

by lowering the activation energy it increases the speed of both forward and reverse pathways of the reaction

Naomi Hernandez-Ramirez 1J

Catalyst aren't products or reactants, therefore a catalyst will not appear in the overall reaction equation; its usually presented as intermediates in the steps and gets canceled during the process

Naomi Hernandez-Ramirez 1J

it won't be on the final because its no longer covered in the curriculum, therefore not needed to know for the exams

Naomi Hernandez-Ramirez 1J

both cancel out at the end; intermediates are made in a reaction by first appearing as a product & catalysts are added into a reaction

Naomi Hernandez-Ramirez 1J

For the final in Chem 14b we did NOT have to draw. <--------Chem 14b was taken Winter Quarter 2021 COVID-19 Zoom university
Our tests were all multiple choice and online, I can't tell you how in person will be

Naomi Hernandez-Ramirez 1J

Percent deprotonation = % of substance that lost its proton
Percent protonation = % of substance that gained a proton

Naomi Hernandez-Ramirez 1J

If the 2nd deprotonation of Ka is less than a 1/1000 of the 1st deprotonation of Ka, ignore the 2nd deprotonation reaction

Naomi Hernandez-Ramirez 1J

units for Q are mol/L, mol/L is the standard form; unless the problem, wants them in different units

Naomi Hernandez-Ramirez 1J

even when you decrease by -2x you still have to include the ^2 in the equilibrium concentration

Naomi Hernandez-Ramirez 1J

The first deprotonation is ignored when dealing with a strong acid, for weak acids, ignore the second deprotonation.

Naomi Hernandez-Ramirez 1J

Both pKa and pKb use -log values with the same base pKa+pKb is the same as saying -log(Ka*Kb)

Naomi Hernandez-Ramirez 1J

I use bar when calculating however you can also use atm, both are similar in value so either would work!

Naomi Hernandez-Ramirez 1J

Kc and K are calculate & are the same thing K it is just used for molar concentrations while Kp is used for partial pressure

Naomi Hernandez-Ramirez 1J

You should assume it's 25ºC or 298K just make sure to look at what the problem is asking

Naomi Hernandez-Ramirez 1J

I hope they do hybrid, I can't imagine how 300+ lecture halls are going to be. If they try and solution this by making enrollment spaces be less than I dont see how people will be able to enroll into the classes they need. I mean people already have a hard time getting classes

Naomi Hernandez-Ramirez 1J

The turnaround for tests was usually a week for this class I would expect by next Sunday to have our final exam grades

Naomi Hernandez-Ramirez 1J

Woke up with an almost heart attack thinking I overslept lol, thankfully iPhones change the time automatically !!!!

Naomi Hernandez-Ramirez 1J

I thought the final was better than the first Midterm, but worse than the second midterm, overall quite fair

Naomi Hernandez-Ramirez 1J

I'm not completely sure, to be quite frank I like being back home. However I guess it depends on how the classes will be.

Naomi Hernandez-Ramirez 1J

I miss making friends in lecture halls I look forward to bcafe and Bplate haha, always the food lol

Naomi Hernandez-Ramirez 1J

I’ve been feeling the burnout alright! What try to do is space out my days give myself breaks a create schedules so that by 4 I’m done with my day.

Naomi Hernandez-Ramirez 1J

Thank you guys!

Naomi Hernandez-Ramirez 1J

Should we expect to see an email with details??

Naomi Hernandez-Ramirez 1J

Cant wait for spring break! Quarter isn’t finished but I sure am, counting the days

Naomi Hernandez-Ramirez 1J

I am content with my MT2 grade but I really would like top know what problems I got wrong or when I went in the wrong direction so it could help me study for the Final ugh.

Naomi Hernandez-Ramirez 1J

I think you'd be fine if you post more, it just won't count

Naomi Hernandez-Ramirez 1J

QUESTION: the final is cumulative right?

Naomi Hernandez-Ramirez 1J

Diddy Riece is okay, I don't think its worth the hype (oops I said it), but have in mind its cash only! Also if you'r e moving to Westwood, you have to at least go once to Fat Sal's!!

Naomi Hernandez-Ramirez 1J

Bridgerton on Netflix--SOOO good, don't recommend watching with family though, but such a binge worthy show!!!

Naomi Hernandez-Ramirez 1J

A pH meter measures the acidity of a substance, usually a liquid by the concentration of H+ ions, from this the substance can be categorized as alkaline or acidic

Naomi Hernandez-Ramirez 1J

I usually use Kelvin and if the problem gives me temperature in Celsius then I just convert.

Naomi Hernandez-Ramirez 1J

thermodynamically favorable = enthalpy decreases and entropy increases (negative dG)

Naomi Hernandez-Ramirez 1J

The grades for MT1 were up in like a week id expect the same.

Naomi Hernandez-Ramirez 1J

Im a bit confused with what Dr. Lavelle says that at least 50% is needed for a C-. Does anyone know what the grade cutoffs are for C's, B's, and A's?

Naomi Hernandez-Ramirez 1J

Dr. Castillo is the professor for 14C and it filled up already...

Naomi Hernandez-Ramirez 1J

This is interesting because my family has had that same debate. How do you feel about adding a few drops of olive oil to the boiling water? My mom has always done this because she says it prevents the pasta from sticking... I read somewhere that putting oil in the water actually coats the pasta wit...

Naomi Hernandez-Ramirez 1J

Heat capacities can not be negative, they must be positive.

Naomi Hernandez-Ramirez 1J

Phase change means when a substance changes its state of matter. For instance water going from liquid to solid than gas, each step is a phase change.

Naomi Hernandez-Ramirez 1J

It depends on the delta G. If delta G is negative than more products are favored and if delta G is positive than reactants are favored

Naomi Hernandez-Ramirez 1J

I wouldn't worry too much, last time Dr. Lavelle emailed us to let us know he was going to upload I assume,e he'll do the same

Naomi Hernandez-Ramirez 1J

I think you'll be good in 14BL its mostly just labs and the exams are very fair!

Naomi Hernandez-Ramirez 1J

Inert gas= a gas which does not react with the reactants or products of the chemical reaction

Naomi Hernandez-Ramirez 1J

∆U = q + w
∆U= change of energy in internal system

Naomi Hernandez-Ramirez 1J

Thank you for these tips! they are helpful tips and I especially think that they good because I didnt have Lavelle last quarter. Will definitely take these not for considerations--but actually our them into practice for MT2

Naomi Hernandez-Ramirez 1J

Oh my gosh i'm cracking up at the post about the chemical principals,
The duke and I by Julia Quinn!!

Naomi Hernandez-Ramirez 1J

I agree, it was harder than expected but it could’ve just been that I felt time was a factor for it

Naomi Hernandez-Ramirez 1J

Hii, When it was mentioned that our midterm would be during our lecture time, does it mean those who have a 10am lecture will take it at 10am, those who have a 1pm lecture will take it at 1pm, etc.? And does anyone know if there will be a lecture recording on Friday? Just want to plan ahead for the...

Naomi Hernandez-Ramirez 1J

Does anyone know how fast the turnaround time is for MT 1 grades? Will we know our score right after or does it take time?

Naomi Hernandez-Ramirez 1J

Yes! we will have zoom proctoring with a 2nd device, lots of info in his email with MT 1 information

Naomi Hernandez-Ramirez 1J

Dr. Lavelle sent out an email with MT 1 information, I'll include a screenshot of where he talks about partial credit.

Naomi Hernandez-Ramirez 1J

I believe its Fridays lecture of Week 3!

Naomi Hernandez-Ramirez 1J

From what I've heard UA sessions and Homework problems!

Naomi Hernandez-Ramirez 1J

not sure if we are but in case, just know that the standard state refers to the element's form at 25ºC and 1atm

Naomi Hernandez-Ramirez 1J

Like previously mentioned, Standard State is 25ºC and 1atm

Naomi Hernandez-Ramirez 1J

Didn't have Lavelle for Chem 14A, does he do a review session before the midterm? or is the homework problems from the outline basically it?

Naomi Hernandez-Ramirez 1J

Hi guys, so what im taking from this is basically ti study/ understand how to do textbook problems because they are similar to what the midterms will be like?

Naomi Hernandez-Ramirez 1J

Hi so if the acid is strong, the pKa will be a smaller value

Naomi Hernandez-Ramirez 1J

don't worry its the same thing, in dividing by 0.5 its the same thing as multiplying it by 2 at the end you should end up with the same result. if not try seeing another factor that might of caused it

Naomi Hernandez-Ramirez 1J

I believe that liquids and solids don't count and we only do the moles of gases

Naomi Hernandez-Ramirez 1J

I believe we would just need to state if the reaction is end or exothermic. The response depends on delta h

Naomi Hernandez-Ramirez 1J

something that helps me remember this is: Exo= outside so energy is released to the outside. Endo= within so energy is absorbed.

Naomi Hernandez-Ramirez 1J

Arti_Patel_3H wrote:
Naomi Hernandez-Ramirez 1J wrote:(Took Chem 14A w/ Scerri) Do any of you have the lockdown browser, Respondus, download link or know where I can find it?

https://download.respondus.com/lockdown ... =228644488 this is the link I used to download Respondus for Lavelle last quarter

THANK YOU!!

Naomi Hernandez-Ramirez 1J

like most I agree that the standard unit for pressure = atm, I know you've been getting Atm and bar, but I think atm is the correct unit

Naomi Hernandez-Ramirez 1J

How do we know the conditions of equilibrium? Would it only be temperature or other conditions as well?

Naomi Hernandez-Ramirez 1J

(Took Chem 14A w/ Scerri) Do any of you have the lockdown browser, Respondus, download link or know where I can find it?

Naomi Hernandez-Ramirez 1J

how do we know the concentrations of each (P and R)? I totally forgot and spaced when he was going over it in lec1

Naomi Hernandez-Ramirez 1J

If equilibrium is temperature dependent would it it also be time dependent? (time from initial temp to equilibrium temp)

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