Search found 107 matches
- Wed Mar 10, 2021 11:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: The Final
- Replies: 17
- Views: 1010
Re: The Final
I would assume so.
- Wed Mar 10, 2021 11:30 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: sapling week 10 #20
- Replies: 3
- Views: 370
sapling week 10 #20
"The presence of a catalyst provides a reaction pathway in which the activation energy of a reaction is reduced by 31.00 kJ⋅mol−1 . Uncatalyzed: A⟶B Ea=115.00 kJ⋅mol−1 Catalyzed: A⟶B Ea=84.00 kJ⋅mol−1 Determine the factor by which the catalyzed reaction is faster than the uncatalyzed reaction a...
- Wed Mar 10, 2021 11:28 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: week 10 sapling #17
- Replies: 1
- Views: 188
week 10 sapling #17
"A certain reaction has an enthalpy of ΔH=34 kJ and an activation energy of Ea=71 kJ. What is the activation energy of the reverse reaction?" Hi, the hints for this problem say to draw out an energy diagram but I still am not getting it. Would someone please be able to lay out the steps to...
- Wed Mar 10, 2021 11:26 pm
- Forum: General Rate Laws
- Topic: sapling week 10 #13
- Replies: 7
- Views: 535
sapling week 10 #13
"The mechanism proposed for the oxidation of iodide ion, I−, by the hypochlorite ion, ClO−, in aqueous solution is shown. ClO−(aq)+H2O(l)⇌HClO(aq)+OH−(aq)fast in both directions I−(aq)+HClO(aq)→HIO(aq)+Cl−(aq) slow HIO(aq)+OH−(aq)→IO−(aq)+H2O(l) fast Complete the rate law for the formation of I...
- Wed Mar 10, 2021 11:22 pm
- Forum: First Order Reactions
- Topic: sapling week 10 #11
- Replies: 5
- Views: 365
sapling week 10 #11
"Dinitrogen pentoxide, N2O5, decomposes by first‑order kinetics with a rate constant of 3.7×10−5 s−1 at 298 K. What is the half‑life, in hours, of N2O5 at 298 K? If [N2O5]0=0.0679 mol⋅L−1, what will be the concentration of N2O5 after 2.7 h? [N2O5]: How much time, in minutes, will elapse before ...
- Sun Mar 07, 2021 8:30 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 48
- Views: 3558
Re: Final
I try and find the hardest most complicated problems in the book to practice before the final.
- Sun Mar 07, 2021 8:27 pm
- Forum: Student Social/Study Group
- Topic: What do you miss / What are you looking forward to?
- Replies: 92
- Views: 16624
Re: What do you miss / What are you looking forward to?
I am a freshman and I am very looking forward to getting to know what life is even like at UCLA because I of course have no clue what to expect.
- Sun Mar 07, 2021 8:25 pm
- Forum: Student Social/Study Group
- Topic: Chem Final
- Replies: 13
- Views: 962
Re: Chem Final
The distribution of questions last quarter was based on the size of the unit.
- Sun Mar 07, 2021 8:24 pm
- Forum: Student Social/Study Group
- Topic: Note Taking
- Replies: 145
- Views: 22516
Re: Note Taking
I find handwritten notes are best for me and I believe there is research showing that writing things out by hand helps to commit it to memory.
- Sun Mar 07, 2021 8:18 pm
- Forum: Student Social/Study Group
- Topic: How do you deal with burnout?
- Replies: 144
- Views: 26827
Re: How do you deal with burnout?
I try to find time to relax and destress and try to get in a mindset where I am not even thinking about school because if you're trying to relax and you're just thinking about all the work you have to do the whole time it's not really relaxing.
- Sat Feb 27, 2021 1:07 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: week 8 sapling #17
- Replies: 2
- Views: 239
week 8 sapling #17
What would the potential of a standard hydrogen electrode (S.H.E.) be under the given conditions?
[H+]=0.46 MPH2=4.9 atm T=298 K
Hi does anyone know what section of the textbook I could reference to try and solve this because honestly I have no clue where to start with this one.
[H+]=0.46 MPH2=4.9 atm T=298 K
Hi does anyone know what section of the textbook I could reference to try and solve this because honestly I have no clue where to start with this one.
- Sat Feb 27, 2021 1:04 pm
- Forum: Balancing Redox Reactions
- Topic: sapling week 8 #18
- Replies: 4
- Views: 374
sapling week 8 #18
"One of the most recognizable corrosion reactions is the rusting of iron. Rust is caused by iron reacting with oxygen gas in the presence of water to create an oxide layer. Iron can form several different oxides, each having its own unique color. Red rust is caused by the formation of iron(III)...
- Sat Feb 27, 2021 1:02 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: sapling week 8 #15
- Replies: 4
- Views: 304
sapling week 8 #15
"Calculate the cell potential for the reaction as written at 25.00 °C , given that [Cr2+]=0.791 M and [Fe2+]=0.0140 M . Use the standard reduction potentials in this table. Cr(s)+Fe2+(aq)↽−−⇀ Cr2+(aq)+Fe(s)" I think the part I may be doing wrong on this is calculating either Q or n but I a...
- Sat Feb 27, 2021 1:01 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: sapling week 8 #12
- Replies: 3
- Views: 1133
sapling week 8 #12
"Calculate the standard free-energy change for the reaction at 25 ∘C. Refer to the list of standard reduction potentials. 2Au3+(aq)+3Ni(s)↽−−⇀2Au(s)+3Ni2+(aq)" So far every time I have tried this problem I have gotten wildly different answers because I gave tried it multiple ways but they ...
- Sat Feb 27, 2021 12:59 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: week 8 sapling #9
- Replies: 1
- Views: 750
week 8 sapling #9
"A galvanic (voltaic) cell consists of an electrode composed of iron in a 1.0 M iron(II) ion solution and another electrode composed of copper in a 1.0 M copper(I) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Refer to the list of standard re...
- Sat Feb 27, 2021 12:57 pm
- Forum: Balancing Redox Reactions
- Topic: week 8 sapling #5
- Replies: 1
- Views: 212
week 8 sapling #5
"Identify the oxidizing and reducing agents in the skeletal (unbalanced) reaction. Then, balance the reaction, including the phase (solid, liquid, etc.) of each species. The reaction takes place in basic aqueous solution. Cl2O7(g)+H2O2(aq)⟶ClO−2(aq)+O2(g) Identify the oxidizing and reducing age...
- Sat Feb 27, 2021 12:55 pm
- Forum: Balancing Redox Reactions
- Topic: #3 week 8 sapling
- Replies: 2
- Views: 198
#3 week 8 sapling
"For a particular redox reaction, NO is oxidized to NO−3 and Cu2+ is reduced to Cu+ . Complete and balance the equation for this reaction in basic solution. The phases are optional." Hi, I am having a hard time with this question for some reason, could someone give me some guidance on how ...
- Sun Feb 21, 2021 10:42 pm
- Forum: Student Social/Study Group
- Topic: grades
- Replies: 8
- Views: 1084
grades
Hi, so I know that the minimum to pass with a C- is 50% but I was wondering, does anyone know what the grade scale is after that?
- Sun Feb 21, 2021 10:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Extra homework problems on Midterm 2
- Replies: 14
- Views: 915
Re: Extra homework problems on Midterm 2
All the problems that relate to each topic are listed under the outlines on the syllabus but those obviously will not all be on the exams.
- Sun Feb 21, 2021 10:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 48
- Views: 3558
Re: Final
I personally did not do great either and I reviewed sapling, textbook, outlines, lecture notes, and went to review sessions but I feel I would have done better if I was more engaged with the studying and not just doing it like I am going through the motions.
- Sun Feb 21, 2021 10:32 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing vs Reducing
- Replies: 55
- Views: 3113
Re: Oxidizing vs Reducing
I try to remember it as oxidize is losing and reducing is gaining, so the oxidizing part gains the electron but the reducing part loses and electron.
- Sun Feb 21, 2021 10:29 pm
- Forum: Balancing Redox Reactions
- Topic: coefficients for oxidation number
- Replies: 22
- Views: 5159
Re: coefficients for oxidation number
No, I don't think so, I think the coefficient balances the equation but is not part of the calculation.
- Sat Feb 20, 2021 7:03 pm
- Forum: Student Social/Study Group
- Topic: Post Midterm 2 De-stressing
- Replies: 92
- Views: 10444
Re: Post Midterm 2 De-stressing
haha that's so funny, that's exactly what I did. The new episode of WandaVision was crazy.
- Sat Feb 13, 2021 11:15 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Material
- Replies: 10
- Views: 623
Re: Midterm Material
Dr.Lavelle emailed saying...
Midterm 2 will not cover any electrochemistry.
Midterm 2 covers:
Outline 3: Thermochemistry (but not the MT1 topics*)
Outline 4: Thermodynamics
*The MT1 topics (different ways of calculating reaction enthalpy) are not covered in MT2.
Midterm 2 will not cover any electrochemistry.
Midterm 2 covers:
Outline 3: Thermochemistry (but not the MT1 topics*)
Outline 4: Thermodynamics
*The MT1 topics (different ways of calculating reaction enthalpy) are not covered in MT2.
- Sat Feb 13, 2021 11:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 2 Content
- Replies: 18
- Views: 911
Re: Midterm 2 Content
Dr.Lavelle emailed saying that "Midterm 2 will not cover any electrochemistry.
Midterm 2 covers:
Outline 3: Thermochemistry (but not the MT1 topics*)
Outline 4: Thermodynamics"
Midterm 2 covers:
Outline 3: Thermochemistry (but not the MT1 topics*)
Outline 4: Thermodynamics"
- Sat Feb 13, 2021 11:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: struggling
- Replies: 73
- Views: 5344
struggling
Hi, so I am struggling in this class. I do all the problems outlined on the syllabus, I watch and rewatch lectures, I take notes on and read the entirety of the textbook sections but I got a pretty bad score on my midterm. Does anyone have any suggestions on what else I could be doing for better ret...
- Sat Feb 13, 2021 10:55 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Sapling #5 week 5 and 6
- Replies: 13
- Views: 731
Sapling #5 week 5 and 6
The molar heat capacity for carbon monoxide at constant volume is CV, m=20.17 J/(K·mol) . An 8.00 -L fixed-volume flask contains CO(g) at a pressure of 2.00 kPa and a temperature of 25.0 °C. Assuming that carbon monoxide acts as an ideal gas and that its heat capacity is constant over the given temp...
- Sat Feb 13, 2021 10:08 pm
- Forum: Student Social/Study Group
- Topic: Culinary Chemistry
- Replies: 239
- Views: 47807
Re: Culinary Chemistry
This is so fun, I noticed the application of chemistry a lot in baking like baking is such an exact science because it's basically just chemical reactions coming together to make the end product, and if you get one of those reactions just a little off the whole thing is wrong.
- Mon Feb 08, 2021 12:01 am
- Forum: Administrative Questions and Class Announcements
- Topic: Grades for Chemistry Community
- Replies: 21
- Views: 1038
Re: Grades for Chemistry Community
The grading was input for week 5 as well even though week 5 was not done, Dr Lavelle sent an email talking about it. I got scared too.
- Mon Feb 08, 2021 12:01 am
- Forum: Administrative Questions and Class Announcements
- Topic: Tips for Concentrating during a test
- Replies: 31
- Views: 1681
Re: Tips for Concentrating during a test
I find a quiet room and just do my best to toon everything out, I know its hard sometimes though.
- Mon Feb 08, 2021 12:00 am
- Forum: Administrative Questions and Class Announcements
- Topic: sapling
- Replies: 4
- Views: 286
sapling
do we know when the rest of the sapling assignments for the quarter will be posted? I know it's a little soon since we haven't started the next topics I just like having it all written out in my planner.
- Sun Feb 07, 2021 11:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterm 2
- Replies: 12
- Views: 808
midterm 2
is midterm 2 cumulative or does it just cover everything we will have covered since midterm 1?
- Sun Feb 07, 2021 11:58 pm
- Forum: Administrative Questions and Class Announcements
- Topic: exam review
- Replies: 6
- Views: 394
exam review
Hi, do we attend any office hours to review our exams?
- Sun Jan 31, 2021 2:37 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorize bond enthalpies / standard enthalpies of formation?
- Replies: 39
- Views: 1681
Re: Memorize bond enthalpies / standard enthalpies of formation?
No, my TA has said we do not need to memorize these and that if we ever need to use them they will be provided.
- Sun Jan 31, 2021 2:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Labs
- Replies: 10
- Views: 638
Labs
Hi, I was wondering when other people are planning on taking 14Bl and 14CL because I am not sure what the best planning would be to work them into my schedule, when do most people take those classes?
- Sun Jan 31, 2021 2:32 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system
- Replies: 43
- Views: 1840
Re: closed system
A closed system prevents volume change because there is no exchange of matter with the system's surroundings so nothing can leave the system so its volume stays consistent.
- Sun Jan 31, 2021 2:31 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Significance of open, closed, isolated
- Replies: 22
- Views: 1262
Re: Significance of open, closed, isolated
Knowing the type of system is important so you are aware if there is any exchange in matter or energy with the system's surroundings because if there is an exchange that would affect the makeup of the system.
- Sun Jan 31, 2021 2:29 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: isolated system examples
- Replies: 4
- Views: 166
Re: isolated system examples
since an isolated system does not exchange energy or matter with its surroundings an example Dr.Lavelle gave during the lecture was a really well-insulated thermos.
- Sun Jan 24, 2021 4:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Question about 14B Exams
- Replies: 38
- Views: 1927
Re: Question about 14B Exams
Midterm 1 covers Chemical Equilibria, Acid and Base Equilibria, and only these Week 3 topics (4D.3; 4D.4; 4D.5; 4E.3). Last quarter it was structured so whichever topic we spent the most time on would have a larger portion of the test so it was proportional to the class.
- Sun Jan 24, 2021 4:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 1 Material?
- Replies: 8
- Views: 406
Re: Midterm 1 Material?
Dr.Lavelle emailed saying that "midterm 1 covers Chemical Equilibria, Acid and Base Equilibria, and only these Week 3 topics (4D.3; 4D.4; 4D.5; 4E.3)."
- Sun Jan 24, 2021 4:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Periodic Tables on Midterm
- Replies: 23
- Views: 1198
Re: Periodic Tables on Midterm
yes, we print out the equations sheet and periodic table from Dr. Lavelle's website to use on the tests.
- Sun Jan 24, 2021 4:51 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 21338
Re: Endothermic v. Exothermic
Yes, endothermic reactions will always have a positive delta H because the change is positive and exothermic reactions will always have a negative delta H because the change is negative.
- Sun Jan 24, 2021 4:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterm
- Replies: 11
- Views: 726
midterm
Has Dr.Lavelle told us if we will be using a zoom for proctoring of the midterms?
- Sat Jan 16, 2021 6:43 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Change in pressure due to inert gas
- Replies: 6
- Views: 281
Re: Change in pressure due to inert gas
An inert gas changes the total pressure of the entire system, it has no effect on the partial pressures of the individual components of the system.
- Sat Jan 16, 2021 6:40 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 19
- Views: 1614
Re: Le Chatelier's Principle
My little "dumbed down" version of it that I remember it with is essential that if the system is acted on it will compensate for that but doing more of the opposite action to keep the original K value.
- Sat Jan 16, 2021 6:38 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Using the ICE table
- Replies: 36
- Views: 1679
Re: Using the ICE table
yes, personally I know ICE tables are used when doing these calculations but I like to use them on most problems just to keep everything organized and make sure I'm not missing anything
- Sat Jan 16, 2021 6:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE table and Molarity units
- Replies: 18
- Views: 943
Re: ICE table and Molarity units
Hi, I would use mol/L just to have consistency and prevent any little mistakes later on.
- Thu Jan 14, 2021 10:48 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Getting two positive x values when using quadratic
- Replies: 43
- Views: 5396
Re: Getting two positive x values when using quadratic
if both x values are positive one will likely be too big to be an option, like it will be larger than the concentration of one of the reactants or products so in that case, you would use the smaller x value.
- Thu Jan 14, 2021 10:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterms
- Replies: 7
- Views: 370
midterms
Hi, I know last quarter for 14B we did our midterms at our discussion section times, does anyone know if we will be continuing to do so this quarter?
- Sun Jan 10, 2021 2:14 pm
- Forum: Ideal Gases
- Topic: Non-Ideal gases?
- Replies: 26
- Views: 1233
Re: Non-Ideal gases?
I believe Dr.Lavelle has said we do not use non-ideal gases in the course but possibly in some upper-division chemistry courses we might.
- Sun Jan 10, 2021 2:10 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Definition
- Replies: 10
- Views: 699
Re: Ideal Gas Definition
we assume all gases are ideal gases even though very few are but by assuming so we are able to use PV=nRT
- Sun Jan 10, 2021 1:59 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction Quotient Definition
- Replies: 7
- Views: 604
Re: Reaction Quotient Definition
we find Q instead of K when the reaction is not at equilibrium. Q can be used to compare to a given K to find if the reaction favors products or reactants.
- Sun Jan 10, 2021 1:48 pm
- Forum: Ideal Gases
- Topic: reversing reactions
- Replies: 83
- Views: 7074
Re: reversing reactions
when a reaction is reversed K is inversed as 1/K
- Sun Jan 10, 2021 1:44 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 6317
Re: Kc vs Kp
The c in Kc refers to concentration and the p in Kp refers to pressure so for equations referring to gases you would use Kp as it refers to the pressure of the gas.
- Sun Jan 10, 2021 1:41 pm
- Forum: Student Social/Study Group
- Topic: Advice for someone who didn't take 14A with professor Lavelle
- Replies: 61
- Views: 4099
Re: Advice for someone who didn't take 14A with professor Lavelle
what I found to be most useful was ensuring I did all the assigned bookwork and then before exams making my own study guide out of questions from each topic that was assigned and doing even more practice.
- Sat Dec 12, 2020 5:54 pm
- Forum: Student Social/Study Group
- Topic: Taking the final on an iPad
- Replies: 4
- Views: 358
Re: Taking the final on an iPad
I think you would be able to as long as you're in the lockdown browser otherwise I do not think you can because you would be able to access other materials on it.
- Sat Dec 12, 2020 5:52 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Questions About Organizing Solutions by pH
- Replies: 2
- Views: 302
Re: Questions About Organizing Solutions by pH
Hi, yes if you want to arrange solutions on their pH, the strong acids will have the lowest pH and the strong bases will have the highest pH so it makes sense to identify these to put them in order. Then of course weak bases will have a lower pH than the strong bases but still higher than the acids ...
- Sat Dec 12, 2020 5:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: other resources
- Replies: 5
- Views: 901
other resources
Hi everyone, I know Dr. Lavelles has provided us with great review resources this week and throughout the whole quarter but if anyone is still feeling those prefinal nerves like I am I just wanted to give a heads up, The Organic Chemistry Tutor on youtube has some really great, short, concise, video...
- Sat Dec 12, 2020 5:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL EXAM QUESTIONS
- Replies: 40
- Views: 3462
Re: FINAL EXAM QUESTIONS
Some of the problems will be from the textbook but not all of them.
- Sat Dec 12, 2020 5:32 pm
- Forum: Student Social/Study Group
- Topic: Winter Break
- Replies: 44
- Views: 3338
Re: Winter Break
I would suggest maybe a week before class starts up again start reviewing the content of 14A similarly to how you are studying for the final.
- Sun Dec 06, 2020 9:08 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Determining Oxidation Numbers
- Replies: 6
- Views: 575
Re: Determining Oxidation Numbers
I remember that we obviously need to charge to be equal to the charge given in the problem so I add all the known charges and then I know the oxidation number of the unknown will make it reach the correct charge from there. For example, if the total charge is known to be +1 and with the given charge...
- Sun Dec 06, 2020 8:59 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: bookwork 6B.1 #5
- Replies: 1
- Views: 192
bookwork 6B.1 #5
can someone explain how they got the pH for d, e, and f for this problem, please? Thank you.
- Sun Dec 06, 2020 8:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B and 14BL
- Replies: 13
- Views: 966
Re: 14B and 14BL
Personally, I am taking 14B and 14BL later on and that is what I have seen other people are doing too but I would have taken them together if I would have had enough units available to do so.
- Sun Dec 06, 2020 8:52 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to find coordination number.
- Replies: 10
- Views: 3771
Re: How to find coordination number.
the coordination number is equal to the number of bonds attached to the central atom
Re: Sapling 1
naming is based on the actual name, not the prefix.
- Sun Nov 29, 2020 2:01 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Chelate
- Replies: 2
- Views: 181
Re: Chelate
A chelate is a compound with a ligand that forms a ring of atoms that includes the central metal atom. They include the bidentate, tridentate, and hexadentate ligands which means they are donating 2, 3, or 6 lone pairs. I hope this helped.
- Sun Nov 29, 2020 1:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: grading
- Replies: 11
- Views: 793
grading
I know in the syllabus it gives us a breakdown of how many point each assignment and each test is worth and says that we have to have a 50% to pass with a -C. Do we know anything else about the grading for this class, like what the break down is for the rest of the letter grades, like what percent w...
- Sun Nov 29, 2020 1:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar vs non-polar for molecules
- Replies: 2
- Views: 220
polar vs non-polar for molecules
To determine if the overall molecule is polar or non-polar it's non-polar if the bonds are non-polar but if the bonds are polar we have to know the molecule's shape and bond angles to see if the polar bonds cancel out and if they do then the molecule if non-polar, correct?
- Sun Nov 29, 2020 1:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar vs non-polar
- Replies: 7
- Views: 433
polar vs non-polar
to determine if the bonds are polar or non-polar we just have to know if the two elements have the same electronegativity or not correct? And if they do have the same it's non-polar and if they're different it's polar?
- Sun Nov 29, 2020 1:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: sapling
- Replies: 4
- Views: 347
sapling
I noticed that under the grades tab on sapling there are three extra credit sections for the Math Review, Practice Drawing Molecules, and Chemical Equations Training. Are these assignments actually worth extra credit towards our grade or were they just input as that because they weren't actually ass...
- Sun Nov 22, 2020 4:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: different shapes given in notes
- Replies: 4
- Views: 382
different shapes given in notes
will all the molecules we have to determine the shape of be one of the shapes given to us in our notes, or are there any other shapes we should know about? Also just to double-check the shapes we have been given are: linear, angular, trigonal planar, trigonal pyramidal, t-shaped, tetrahedral, see-sa...
- Sun Nov 22, 2020 4:43 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving
- Replies: 26
- Views: 1637
Thanksgiving
Will we still have a lecture on Friday the week of Thanksgiving? I know we're supposed to have that day off but I know on Veterans day we had a lecture.
- Sun Nov 22, 2020 4:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: book problem 2E.5
- Replies: 3
- Views: 230
book problem 2E.5
2E.5 (a) What is the shape of a ion? (b) What is the expected OClO bond angle?
- Sun Nov 22, 2020 4:39 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 496175
Re: Final Jitters
I try to not stay up too late the night before studying, and if anything do maybe a quick review of the topics you feel you need it in the most. The night before I like to meditate or do yoga before bed and make sure I get a good night's sleep. I have my discussion early in the morning but I try to ...
- Sun Nov 22, 2020 4:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: final
- Replies: 5
- Views: 332
final
do we know yet if the final will be like the midterm and just cover the most recent topics, or will it be cumulative?
- Sun Nov 22, 2020 4:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: shape
- Replies: 6
- Views: 360
shape
I understand how to determine the shape based on the 3d models but I'm not 100% on how to do so without, could anyone please give me a basic overview on how to do so. I know this is a bit of a silly question, but thank you.
- Sun Nov 15, 2020 11:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B and 14BL
- Replies: 6
- Views: 477
14B and 14BL
Hi, I am currently trying to plan out my classes for next quarter. I was not sure if it is required to take 14B and 14BL at the same time, because the final for 14BL conflicts with the final for my math class so I would rather not risk that overlap. Does anyone have any recommendations for what I sh...
- Sun Nov 15, 2020 10:57 pm
- Forum: Dipole Moments
- Topic: Electric Dipole notation [ENDORSED]
- Replies: 1
- Views: 98
Electric Dipole notation [ENDORSED]
I know in the textbook we are given the original as well as the modern notation for showing an electric dipole. The textbook says they use the modern notation, is that what we should use as well?
- Sun Nov 15, 2020 9:38 pm
- Forum: Resonance Structures
- Topic: bookwork 2C.15
- Replies: 2
- Views: 146
bookwork 2C.15
"2C.15 Two contributions to the resonance structure are shown below for each species. Determine the formal charge on each atom and then, if possible, identify the Lewis structure of lower energy for each species." How would we tell which lewis structure has lower energy based on the lewis ...
- Wed Nov 11, 2020 7:12 pm
- Forum: Lewis Structures
- Topic: homework 2B.3
- Replies: 5
- Views: 296
homework 2B.3
"2B.3 Draw the Lewis structure of BrF3" for this problem why does the Br in the lewis structure have 10 electrons?
- Tue Nov 10, 2020 11:28 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.15
- Replies: 2
- Views: 154
2A.15
"2A.15 Write the most likely charge for the ions formed by each of the following elements: (d) Ga" why will the charge of Ga be +3?
- Sun Nov 08, 2020 11:45 pm
- Forum: Ionic & Covalent Bonds
- Topic: resources
- Replies: 7
- Views: 272
resources
Hi, I am struggling a bit with this section so far. Does anyone know of any good youtube channels or any other resources that I could use to supplement the resources given to us through this class?
- Sun Nov 08, 2020 11:40 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Equation
- Replies: 16
- Views: 735
Re: Formal Charge Equation
L is the number of unpaired electrons and you should be able to find this by just counting the number of unpaired dots in the Lewis Structure model.
- Sun Nov 08, 2020 11:39 pm
- Forum: Octet Exceptions
- Topic: specific exceptions
- Replies: 3
- Views: 161
specific exceptions
are there any exceptions to the octet rule we need to know off the top of our heads or will we be able to tell when we do the configurations if they are an exception all the time?
- Sun Nov 08, 2020 11:36 pm
- Forum: Lewis Structures
- Topic: Writing Lewis Structures and Balancing Formal Charge
- Replies: 6
- Views: 285
Re: Writing Lewis Structures and Balancing Formal Charge
Hi, I believe a good thing to keep in mind for this is that when the formal charge is zero that is when it is most stable so that is the ideal state.
- Sun Nov 01, 2020 11:40 pm
- Forum: Photoelectric Effect
- Topic: sapling #22
- Replies: 2
- Views: 308
sapling #22
You use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0237 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts?
- Sun Nov 01, 2020 10:38 pm
- Forum: DeBroglie Equation
- Topic: sapling
- Replies: 4
- Views: 288
Re: sapling
so on this problem, I got the energy for the photon easily but for some reason, the energy for the electron is giving me trouble. Could someone please walk me through that part a little more thoroughly? I've done it a couple of times now and I'm still not sure what I'm doing wrong.
- Sun Nov 01, 2020 10:26 pm
- Forum: Trends in The Periodic Table
- Topic: sapling #23
- Replies: 6
- Views: 308
sapling #23
The electron affinity of thulium has been measured by a technique known as laser photodetachment electron spectroscopy. In this technique, a gaseous beam of the anions of an element is bombarded with photons from a laser. Electrons from the anion are then ejected and their energies are detected. The...
- Sun Nov 01, 2020 9:46 pm
- Forum: DeBroglie Equation
- Topic: sapling
- Replies: 4
- Views: 288
sapling
The E.coli bacterium is about 2.0 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength.
how would I start this problem to find the energy of the photon as well as the energy of the electron?
how would I start this problem to find the energy of the photon as well as the energy of the electron?
- Sun Nov 01, 2020 8:20 pm
- Forum: Photoelectric Effect
- Topic: sapling problem
- Replies: 2
- Views: 326
sapling problem
"As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that the microwaves "herd" electrons into "pointy" areas of the metal object, from which the electrons j...
- Fri Oct 30, 2020 5:26 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: sapling #6
- Replies: 2
- Views: 171
sapling #6
"The electron in a hydrogen atom is excited to the n=6 shell and emits electromagnetic radiation when returning to lower energy levels. Determine the number of spectral lines that could appear when this electron returns to the lower energy levels, as well as the wavelength range in nanometers.&...
- Sun Oct 25, 2020 10:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Constants, Equations, and Periodic Table
- Replies: 3
- Views: 314
Constants, Equations, and Periodic Table
For the midterm, should we be using the printable lists of constants and equations off of Dr. Lavelle's website or should we use the one he has linked to buy through Amazon.
- Sun Oct 25, 2020 9:56 pm
- Forum: Properties of Light
- Topic: Textbook Questions and Midterm
- Replies: 6
- Views: 388
Re: Textbook Questions and Midterm
Dr. Lavelle's email stated this midterm only covers up to last Wednesday's lecture, homework 1D, and up to sapling homework problem 19. He also said the "Review of Chemical and Physical Principles" as well as up to the tenth bullet point of the "Quantum World" outline is the cont...
- Sun Oct 25, 2020 9:49 pm
- Forum: DeBroglie Equation
- Topic: Derivation of Equations on Midterm?
- Replies: 17
- Views: 711
Re: Derivation of Equations on Midterm?
I believe we just have to have an understanding of how the equations were derived but I do not believe we will be required to actually show how they were derived.
- Sun Oct 25, 2020 9:39 pm
- Forum: Significant Figures
- Topic: Sig Figs and Constants on Exams
- Replies: 9
- Views: 660
Re: Sig Figs and Constants on Exams
Hi, I have noticed that in lectures and practice problems the constants are generally rounded but he has said to keep all values and not round until the end number to ensure you get the correct value and number of sig figs so I would not round at first just to be safe.
- Sun Oct 25, 2020 9:34 pm
- Forum: SI Units, Unit Conversions
- Topic: conversion factors
- Replies: 8
- Views: 525
conversion factors
are there any specific conversion factors we are expected to know for the midterm that are not basic common knowledge ones?
- Sun Oct 18, 2020 11:36 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Book Problem 1E.7
- Replies: 1
- Views: 97
Book Problem 1E.7
For 1E.7 in the textbook, how would we "Determine whether each of the following electron configurations represents the ground state or an excited state of the atom given." based on the model that was given?
- Sun Oct 18, 2020 11:33 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations that dont follow the pattern
- Replies: 3
- Views: 854
Electron Configurations that dont follow the pattern
when predicting an electron configuration, how would we know if a certain element will follow the pattern or not?
- Thu Oct 15, 2020 11:48 pm
- Forum: DeBroglie Equation
- Topic: book problem 1B.15
- Replies: 1
- Views: 90
book problem 1B.15
1B.15 The velocity of an electron that is emitted from a metallic surface by a photon is 3.6 × 10 3 km ⋅ s − 1 . (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50 × 10 16 Hz . How much ener...
- Thu Oct 15, 2020 11:16 pm
- Forum: Photoelectric Effect
- Topic: 1B.9
- Replies: 1
- Views: 104
1B.9
"1B.9 A lamp rated at 32 W ( 1 W = 1 J ⋅ s − 1 ) emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?" would anyone be able to give me a step by step explanation on how to do t...