Search found 75 matches

Fri Mar 13, 2020 8:42 am
Forum: Administrative Questions and Class Announcements
Topic: UA Final Review - Kate, Riya, Matthew
Replies: 13
Views: 1165

Re: UA Final Review - Kate, Riya, Matthew

what a wild way to end winter quarter! thank you all for working so diligently in order to support our continued academic success. Stay safe everyone.
Tue Mar 10, 2020 11:00 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 127
Views: 33507

Re: Final Jitters

these are all great suggestions. but now i'm feeling very nervous about the undecided plans for our final exam now that classes are cancelled. Who thinks it will still go as scheduled for Sunday?
Tue Mar 10, 2020 10:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 63
Views: 4131

Re: Step Up Sessions

due to classes now being cancelled, will step-up/review sessions presume as scheduled or are those all cancelled as well?
Mon Mar 02, 2020 10:15 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2 topics
Replies: 11
Views: 83

Re: test 2 topics

thank you everyone!
Sun Mar 01, 2020 8:10 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2 topics
Replies: 11
Views: 83

test 2 topics

Can someone tell me an idea of what all will be on test 2??
Mon Feb 24, 2020 10:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N.17
Replies: 1
Views: 45

6N.17

consider the cell Ag I Ag+ (aq. 5.0 mmol.L^-1)II Ag+ (aq 0.15 mol.L^-1)I Ag. can this cell do work? if so, what is the maximum work that it can perform (per mole of Ag)?
Mon Feb 24, 2020 10:00 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: homework question 6M.3
Replies: 2
Views: 66

homework question 6M.3

predict the standard potential of each of the following galvanic cells:
(a) Pt I Cr^3+, Cr^2+ II Cu^2+ I Cu

(b) Ag I AgI I I^- II Cl^- I AgCl I Ag

(c) Hg I Hg2Cl2 I Cl- II Hg2 ^2+ I Hg

(d) C I Sn^4+, Sn^2+ II Pb^4+, Pb^2+ I Pt
Mon Feb 24, 2020 9:51 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: homework question 6L.9
Replies: 2
Views: 69

homework question 6L.9

(a) write balanced half-reactions for the redox reactions of an acidified solution of potassium permanganate and iron (II) chloride. (b) write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction.
Mon Feb 24, 2020 9:39 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: homework question 6L.1
Replies: 3
Views: 88

homework question 6L.1

calculate the standard reaction gibbs free energy for the following cells:
(a) 2 Ce^4+ (aq) + 3I^- (aq) > 2 Ce^3+ (aq) + I3^- (aq), Ecell = +1.08V
(b) 6 Fe^3+ (aq) + 2 Cr^3+ (aq) + 7 H20 (l) > 6 Fe^2+ (aq) + Cr2o7^2- (aq) + 14 H+ (aq), Ecell = -1.29V
Wed Feb 12, 2020 4:18 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pizza rolls question 2D
Replies: 2
Views: 96

pizza rolls question 2D

What is the initial reaction quotient when 3.2g of NH4HS is placed in a 2.0L vessel along
with 1.47 mol of NH3 and 2.85 mol H2S?
Wed Feb 12, 2020 1:33 pm
Forum: Student Social/Study Group
Topic: midterm location
Replies: 1
Views: 47

midterm location

very random, but can someone please tell me where broad is??? I have never been there before!
Wed Feb 12, 2020 11:17 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: midterm exam
Replies: 1
Views: 49

midterm exam

will all the sections of thermodynamics be on the midterm exam? Just need some clarification.
Mon Jan 27, 2020 11:51 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: homework question 4A.3
Replies: 6
Views: 63

homework question 4A.3

Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump is 3.0 cm and the pump is depressed 20 cm with a pressure of 2.00 atm. (a) how much work is done in the compression? (b) is the work positive or negative with respect to the air in the pump? (c) what is the ...
Mon Jan 27, 2020 11:40 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Order of homework for Thermochem unit
Replies: 6
Views: 66

Re: Order of homework for Thermochem unit

I would say it won't hurt to just get the extra practice, especially since everything will be a fair shot on the midterm/final
Sun Jan 19, 2020 6:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: question 6B.7
Replies: 4
Views: 36

question 6B.7

The pH of several solutions was measured in research laboratories of a food company; convert each of the following pH values into the molar concentration of H3O+ ions: (a) 3.3 (the pH of sour orange juice); (b) 6.7 (the pH of the saliva sample); (c) 4.4 (the pH of beer); (d) 5.3 (the pH of a coffee ...
Sun Jan 19, 2020 6:17 pm
Forum: Ideal Gases
Topic: homework #3
Replies: 16
Views: 213

Re: homework #3

just realized this as I was going through the class website! thanks!
Sun Jan 19, 2020 6:10 pm
Forum: Phase Changes & Related Calculations
Topic: lecture on 1/17
Replies: 3
Views: 62

lecture on 1/17

would anyone be willing to give me a brief rundown of what lavelle covered in lecture on friday? I was out of town traveling for a competition and was not able to attend.
Sun Jan 19, 2020 6:00 pm
Forum: Ideal Gases
Topic: homework #3
Replies: 16
Views: 213

homework #3

does anyone know what problem set we are supposed to choose homework problems from for week three?? is it outline 2 or are we still focusing on chemical equilibrium?
Sun Jan 19, 2020 5:56 pm
Forum: Ideal Gases
Topic: Topics on Test 1
Replies: 37
Views: 417

Re: Topics on Test 1

Not sure if this was covered in section, but are there specific equations/formulas we should for sure now for test 1??

(e.g. pH + pOH = kw)
Sun Jan 19, 2020 5:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework problem 5.I.15
Replies: 4
Views: 68

Re: Homework problem 5.I.15

Honestly ice tables are just a quick to check your work, but from what I understand it is required that you use one to solve such questions on tests/exams
Sun Jan 19, 2020 5:52 pm
Forum: Administrative Questions and Class Announcements
Topic: final exam
Replies: 6
Views: 118

Re: final exam

whoever finds out this information first, please feel free to post it here!
Sat Dec 07, 2019 1:09 pm
Forum: Student Social/Study Group
Topic: another practice problem (not from midterm/ test 1 or 2)
Replies: 1
Views: 55

another practice problem (not from midterm/ test 1 or 2)

A drink contains 1.2 * 10^-10M of hydroxide ions, what is the pH of this drink?
Sat Dec 07, 2019 1:07 pm
Forum: Student Social/Study Group
Topic: Study tips
Replies: 3
Views: 60

Re: Study tips

what do you all think are the MOST important constants/equations we should memorize for the exam? (e.g. DeBroglie)
Sat Dec 07, 2019 1:05 pm
Forum: Student Social/Study Group
Topic: not a question from the midterm or past tests, but a practice problem that i received from my PLF session
Replies: 1
Views: 67

not a question from the midterm or past tests, but a practice problem that i received from my PLF session

A cup of water is sitting at 25 degrees C. What is the molar concentration of hydronium ions in the cup? How about hydroxide ions?
Sat Dec 07, 2019 12:59 pm
Forum: Student Social/Study Group
Topic: midterm question 4B
Replies: 1
Views: 51

midterm question 4B

If 100KJ of energy was absorbed by the gas sample, how many photons in total caused electronic excitations? How many moles of hydrogen were excited assuming one photon interacted with one unique hydrogen atom?? Even though I already looked over the solutions to the exam, I'm still quite confused abo...
Sat Dec 07, 2019 12:55 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR of S02
Replies: 4
Views: 155

Re: VSEPR of S02

Correct, the shape for SO2 is bent

Remember that the VSEPR formula is: AXnEm
A= central atom
X= attached atom
E= lone pair
Sat Dec 07, 2019 12:50 pm
Forum: Sigma & Pi Bonds
Topic: pi bonds
Replies: 5
Views: 174

Re: pi bonds

always remember the first bond must be a sigma bond which makes the rest pi bonds
Sat Dec 07, 2019 12:49 pm
Forum: Naming
Topic: Metals
Replies: 6
Views: 53

Re: Metals

so does this mean that when you are naming metals, you just add -ate to the end? when is it -ite or -ide?
Sat Dec 07, 2019 12:45 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 127
Views: 33507

Re: Final Jitters

Do some yoga/meditation, take study breaks as needed (maybe try and get off campus for a little if you can)
The best thing to do before an exam is not cloud your mind. We retain information best when we study refreshed and with a good mindset.
Sat Dec 07, 2019 12:43 pm
Forum: Limiting Reactant Calculations
Topic: Stoich
Replies: 1
Views: 106

Re: Stoich

In a way, some of the concepts can be considered stoichiometry because we do deal with the products and reactants of chemical reactions... but in a broader sense no, not really it is much more!!
Sat Dec 07, 2019 12:41 pm
Forum: Significant Figures
Topic: Sig Figs on Midterm Q4 Part 2
Replies: 3
Views: 149

Re: Sig Figs on Midterm Q4 Part 2

Can someone please explain how they solved this question? because i got it wrong on the midterm :/
Sat Dec 07, 2019 12:26 pm
Forum: Student Social/Study Group
Topic: Naming Compounds (general question)
Replies: 2
Views: 129

Re: Naming Compounds (general question)

if you look at questions 27-32 on the final exam review it asks you to either name the compound or give the molecular formula. so id assume that for the exam Lavelle wants us to know both
Sat Dec 07, 2019 12:20 pm
Forum: Naming
Topic: Abbreviations (oxalato)
Replies: 2
Views: 49

Re: Abbreviations (oxalato)

pretty sure to get the answer completely correct you have to write it out fully (so your 2nd answer would be right)
Sat Dec 07, 2019 12:18 pm
Forum: Student Social/Study Group
Topic: Study tips
Replies: 3
Views: 60

Re: Study tips

actual study tip:
-do both the final review and the mini one that was posted!! rumor has it that Lavelle sometimes pulls questions from them and uses them as test questions
Sat Dec 07, 2019 12:16 pm
Forum: Student Social/Study Group
Topic: Study tips
Replies: 3
Views: 60

Re: Study tips

unless you are good at math in your head, I suggest you bring one with you the final (non graphing only of course)
Sat Dec 07, 2019 12:15 pm
Forum: Empirical & Molecular Formulas
Topic: Midterm question 1
Replies: 6
Views: 236

Re: Midterm question 1

What's the step to step process on how to solve this problem? because I am lost

I get that that you have to first convert from grams to moles... but what do you do next?
Sat Dec 07, 2019 12:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar or Nonpolar
Replies: 3
Views: 125

Re: Polar or Nonpolar

if the charge distribution of the shape is symmetrical it is nonpolar
if the charge distribution of the shape is asymmetrical it is polar
Sat Dec 07, 2019 12:01 pm
Forum: General Science Questions
Topic: Textbook
Replies: 2
Views: 90

Re: Textbook

YES. Pretty the same concepts we will be learning, just expanding upon. Hold on to those textbooks people! :)
Sat Dec 07, 2019 11:54 am
Forum: Properties of Electrons
Topic: Mass of an electron
Replies: 9
Views: 329

Re: Mass of an electron

note: as for the midterm and final exam we are only given a periodic table, NOT the list of equations/constants. we just have to know them.
Sat Dec 07, 2019 11:47 am
Forum: Student Social/Study Group
Topic: Study tips
Replies: 7
Views: 238

Re: Study tips

Honestly doing both practicing problems and studying old test questions would be best. Who knows, past questions could be reused on the final :/
Sat Dec 07, 2019 11:43 am
Forum: Lewis Acids & Bases
Topic: Water
Replies: 2
Views: 37

Re: Water

I'm gonna assume you mean "conjugated"???
Sat Dec 07, 2019 11:16 am
Forum: DeBroglie Equation
Topic: converting from nm to m
Replies: 3
Views: 144

converting from nm to m

Are we supposed to convert to nm when solving problems using the DeBroglie equation??? or can we just leave our answers in meters?
Sat Dec 07, 2019 11:11 am
Forum: Bronsted Acids & Bases
Topic: HCl vs HClO
Replies: 2
Views: 56

Re: HCl vs HClO

by definition: "a more stable conjugate base means a stronger acid"

Also, the size and difference in electronegativity of HCl makes it a stronger acid
Sat Dec 07, 2019 10:59 am
Forum: Bronsted Acids & Bases
Topic: Strong Vs. Weak Acids and Bases
Replies: 2
Views: 97

Re: Strong Vs. Weak Acids and Bases

I would suggest you just go ahead and memorize them. That may make things much easier if you already know them! What about coming up with a fun mnemonic to help memorize them?
Thu Dec 05, 2019 9:20 pm
Forum: Amphoteric Compounds
Topic: 6A.17
Replies: 2
Views: 115

Re: 6A.17

amphoteric= means that the compound reacts as both as a base and as an acid
some examples-
2. zinc oxide
Thu Dec 05, 2019 9:10 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8023
Views: 1404287

Re: Post All Chemistry Jokes Here

Heres a fun way to memorize the three (OH)2 strong bases:

"drink your milk (Ca (OH)2) so you can be a strong (Sr (OH)2) baller (Ba (OH)2)"!!!
Thu Dec 05, 2019 8:59 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: naming compounds
Replies: 1
Views: 36

Re: naming compounds

when naming a compound, the roman numeral serves to represent the charge and oxidation state of the metal ion!
Thu Dec 05, 2019 8:57 pm
Forum: Bronsted Acids & Bases
Topic: HF is a weak acid?
Replies: 8
Views: 136

Re: HF is a weak acid?

if anyone has some tips/tricks on how to easily identify strong/weak acids and bases, please share!!!
Sun Nov 24, 2019 4:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: square planar vs tetrahedral
Replies: 5
Views: 66

Re: square planar vs tetrahedral

in a tetrahedral the central atom is surrounded by 4 substituent atoms vs in a square planar the central atom is surrounded by any amount of substituent atoms
Sun Nov 24, 2019 4:28 pm
Forum: Student Social/Study Group
Topic: Test 2 and Final
Replies: 18
Views: 226

Re: Test 2 and Final

Well since most discussion sections are cancelled this week due the thanksgiving break, we will more than likely get test 2 back either in class monday or wednesday (11/25 or 27) or not until week 10 in section. But i'm not sure if the TA's will just post grades in Myucla before handing them back......
Sun Nov 24, 2019 4:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 33

Re: Ligands

ligands have at least one donor atom with an electron pair used to form covalent bonds with the central atom
3 types:
1. monondentate (e.g. chloride ion)
2. bidentate (e.g. oxalate ion)
3. polydentate (e.g. EDTA)
Thu Nov 14, 2019 8:35 pm
Forum: General Science Questions
Topic: Midterm
Replies: 7
Views: 134

Re: Midterm

Talk to your TA for sure, either in section or go to their office hours. Also go over the solutions to the exam on the class website so you can see the point distribution for each question. I did that and actually ended getting 7 points added to my total grade!
Thu Nov 14, 2019 8:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 11
Views: 109

Re: Test 2

Suggestions to study:
-VSEPR models
-dipoles
-molecular shape names... MEMORIZE (e.g. trigonal planar)

we honestly have not learned much since after the midterm
Thu Nov 14, 2019 8:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape Name
Replies: 17
Views: 269

Re: Molecular Shape Name

We can all agree that based upon what we've recently learned in lecture, VSEPR and molecular shape naming is basically all that will be on test 2!
Thu Nov 14, 2019 8:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing Molecular Structures
Replies: 8
Views: 77

Re: Drawing Molecular Structures

anyone have an example of this? I'm still practicing drawing the structures
Tue Nov 12, 2019 7:45 pm
Forum: Amphoteric Compounds
Topic: Amphiprotic
Replies: 11
Views: 129

Re: Amphiprotic

Amphiprotic= a substance that can both accept and donate a proton (has characteristics of both an acid and a base)

amphiprotic vs. amphoteric:
-a substance is amphoteric when its reaction acts as an acid and as a base
-amphiprotic only applies to protic compounds
Tue Nov 12, 2019 7:38 pm
Forum: Bond Lengths & Energies
Topic: Veteran's Day Jokes
Replies: 1
Views: 85

Re: Veteran's Day Jokes

I tell bad chemistry jokes, because all the good ones "Argon"...
Tue Nov 12, 2019 7:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR model
Replies: 4
Views: 174

Re: VSEPR model

VSEPR= valence shell electron pair repulsion theory

*p.s. not quite sure on how to determine formula yet
Sun Oct 27, 2019 8:39 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 5
Views: 59

Re: Resonance

adding to that, resonance means that some lewis structures have multiple bonds in different equivalent locations

(e.g. from lecture NO3^-)
Sun Oct 27, 2019 8:34 pm
Forum: Ideal Gases
Replies: 147
Views: 104566

going to be honest, I only use the textbook to get homework/practice problems. to me, too much reading makes it confusing, so I mainly utilize my lecture notes and do lots of practice.
Sun Oct 27, 2019 8:32 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 5
Views: 58

Re: Drawing Lewis Structures

does anyone have any tips for making sure that you have enough valence electrons drawn when accounting for double bonds?
Sun Oct 27, 2019 8:29 pm
Forum: Resonance Structures
Topic: delocalized electrons
Replies: 3
Views: 35

Re: delocalized electrons

by definition: a delocalized electron is an electron that is not associated with a single atom/covalent bond

however, I'm also not quite sure why the lewis structure doesn't capture this effect???
Sun Oct 20, 2019 10:07 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8023
Views: 1404287

Re: Post All Chemistry Jokes Here

QA: Why can't you trust an atom?
A: They make up everything!
Sun Oct 20, 2019 10:06 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8023
Views: 1404287

Re: Post All Chemistry Jokes Here

Are you made of copper and tellurium?
because you're Cu Te

lol
Sun Oct 20, 2019 10:04 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Replies: 1
Views: 59

Good question!!! Chemistry is strange... this calls for an answer from Dr. Lavelle
Sun Oct 20, 2019 10:02 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: How to use it
Replies: 5
Views: 86

Re: How to use it

what equation?
Sun Oct 20, 2019 10:00 pm
Forum: Photoelectric Effect
Topic: Video Module Assessment
Replies: 1
Views: 57

Re: Video Module Assessment

step 1= convert nm to m 1nm= 10^9m so... 194nm = 1.94 x 10^-7m step 2= use speed of light formula: c=(wavelength)(frequency) 3.10 x 10^8= (1.94 x 10^-7m)(frequency) frequency= 1.546 x 10^15 Now you can plug the frequency into the formula for kinetic energy: E=hv E= (6.626 x 10^-34)(1.546 x 10^15)= 1...
Sun Oct 20, 2019 9:51 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Number
Replies: 4
Views: 64

Re: Quantum Number

honestly, just know the rules on how to find them!
Wed Oct 09, 2019 10:54 pm
Forum: Einstein Equation
Topic: Numbers to memorize [ENDORSED]
Replies: 37
Views: 1732

Re: Numbers to memorize[ENDORSED]

All I would say, is that for test 1 don't worry about having constants or unit conversions memorized (as they will be given), but for future reference (e.g. the midterm and final) to know and understand them.
Wed Oct 09, 2019 10:51 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 5080

Re: Test 1[ENDORSED]

PSA: don't forget a calculator for the test!!
Sun Oct 06, 2019 9:12 pm
Forum: Significant Figures
Topic: Reviewing Sig Figs
Replies: 3
Views: 70

Re: Reviewing Sig Figs

Khan Academy definitely has some helpful videos that can help with practicing sig figs!
Sun Oct 06, 2019 9:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Posts
Replies: 6
Views: 94

Re: Posts

Random question, but does anyone have any advice/suggestions on things to post on here in for future weeks???
(Besides just posting homework questions)
Sun Oct 06, 2019 9:00 pm
Forum: SI Units, Unit Conversions
Topic: Homework Vs. Test
Replies: 3
Views: 96

Re: Homework Vs. Test

I know for a fact that all constants and equations are given. But as for the molecular vs empirical formula section, just in case I would practice finding them when it is not given!
Wed Oct 02, 2019 4:27 pm
Forum: Limiting Reactant Calculations
Topic: M.9
Replies: 5
Views: 141

Re: M.9

Yes, to find the net ionic equation, start by balancing the equation first... -i don't believe we've gone over this in lecture yet, but the second step is to break all of the strong electrolytes into the ions they form -last step= any that are aqueous on both sides of the chemical equation get cance...
Wed Oct 02, 2019 4:19 pm
Forum: Empirical & Molecular Formulas
Topic: 5 Homework Problems Due
Replies: 21
Views: 306

Re: 5 Homework Problems Due

I agree with what most people have posted... i think its best that you try and practice problems for a variety of sections just as preparation for exams. In Dr. Lavelle's syllabus he even notes that 1 out of 8 homework questions are used in exams, so there's a possibility that you know some answers ...