Search found 39 matches
- Wed Feb 13, 2019 4:13 pm
- Forum: General Science Questions
- Topic: Midterm Formulas
- Replies: 6
- Views: 40
Re: Midterm Formulas
I can't really say everything that won't be given on the midterm but this is all the equations and constants he will give us, plus he said to give us constants specific to the problems. You might have to use variations of these equations but hope this helps! https://lavelle.chem.ucla.edu/wp-content/...
- Tue Feb 12, 2019 7:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heat Release from ice (0C) to water (20C)
- Replies: 4
- Views: 1764
Re: Heat Release from ice (0C) to water (20C)
The one that starts with 6 is 6.01 kJ*mol^-1. This is per mole and the one Lavelle used is per gram and isn't given to us on the constant sheet. The two options here are to remember and use that one for this problem or convert the grams of ice to moles and use the 6.01kJ/mol (If you convert to moles...
- Sun Feb 10, 2019 10:23 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
- Replies: 47
- Views: 1679
Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Thank you thank you for all this :D
- Sun Feb 10, 2019 10:19 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Lecture notes 2/8/19
- Replies: 3
- Views: 39
Re: Lecture notes 2/8/19
Yooo this is super useful thank you thank you
- Sun Feb 10, 2019 9:20 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Study Guides
- Replies: 15
- Views: 163
Re: Study Guides
Not sure but if you go the step-up/workshop sessions you can probably get some more focused worksheets
- Tue Feb 05, 2019 3:32 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4.D.11 (7th ed)
- Replies: 2
- Views: 20
4.D.11 (7th ed)
Part b asks "How much heat is absorbed in the oxidation of 5.45L of nitrogen measured at 1 atm and 273k?" The only thing I can think of is to use the ideal gas law because we have p v and t but that gives the the moles and where do we go from there?
- Sun Feb 03, 2019 10:10 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Adiabatic
- Replies: 4
- Views: 22
Re: Adiabatic
Adiabatic is a quick process that does not allows for heat transfer, but the temperature pressure and volume can all change. All change in energy would be from Work.
- Sun Feb 03, 2019 10:04 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Isochoric
- Replies: 4
- Views: 22
Re: Isochoric
The volume is held constant, on a PV diagram it would a vertical line meaning the pressure and temperature can change. Since it is a vertical line there is no work being done and the change in internal energy is all heat.
- Sun Feb 03, 2019 9:55 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Isobaric
- Replies: 2
- Views: 16
Re: Isobaric
The pressure is constant. On a Pressure-Volume Diagram the line would be a horizontal line
- Sun Jan 27, 2019 10:05 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lecture Slides
- Replies: 5
- Views: 39
Re: Lecture Slides
No he doesn't. You could get the notes from someone and I'm sure he could clear up any confusions you still have in like office hours or something :)
- Sun Jan 27, 2019 10:01 pm
- Forum: Phase Changes & Related Calculations
- Topic: State functions
- Replies: 2
- Views: 17
Re: State functions
Work is not a state function because its current state depends on things preceding it. The example in the book is two experiments, one where a gas expands pushing a piston which pushes against water; work is done here because there is an external force. The second has a gas push a piston into a vacu...
- Sun Jan 27, 2019 9:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 14
- Views: 79
Re: closed vs isolated
A closed system has a fixed amount of matter but can exchange energy with the surroundings/environment. In an isolated system the system can't exchange matter or energy with the surroundings.
- Thu Jan 17, 2019 10:41 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pKa and pKb
- Replies: 4
- Views: 31
pKa and pKb
I'm getting a bit confused but what does a high pKa mean in comparison to a low pKa, and same with pKb. I know that a low pKa means a high pKb but would that be a stronger acid/weak base or a stronger base/weak acid.
- Wed Jan 16, 2019 7:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice table coefficients [ENDORSED]
- Replies: 6
- Views: 43
Re: Ice table coefficients [ENDORSED]
If you look on the example 5I.3 7th ed on p.419-420 you see in the change portion of the ICE that there can be a +2x or -2x. These come from the stoichiometric coefficients of the chemical equations
- Tue Jan 15, 2019 3:08 pm
- Forum: General Science Questions
- Topic: Autoprotolysis
- Replies: 3
- Views: 38
Re: Autoprotolysis
Autoprotolysis is the proton transfer between the same type of molecule. In the case of water it favors being 2H2O rather than being H3O+ and OH-. This leads to autoprotolysis for water at 25 C being 1*10^-14 with H3O and OH being equal
- Sun Dec 09, 2018 7:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grade View
- Replies: 7
- Views: 149
Re: Final Grade View
For the midterm it took them like a week so I assume that it will be posted around Next Sunday
Good luck with finals! :D
Good luck with finals! :D
- Thu Dec 06, 2018 11:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 3565
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
The real mvp here
- Tue Dec 04, 2018 5:26 pm
- Forum: Student Social/Study Group
- Topic: Tuesday Review Session
- Replies: 1
- Views: 25
Tuesday Review Session
Does anyone have any notes they can share for the review session that was on Tuesday 12:30-2 pm with Daniel, wasn't able to go because of work so thank you very much!
- Sat Dec 01, 2018 11:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 186
- Views: 39278
Re: Saying Thank You to Dr. Lavelle
Dr. Lavelle i just want to say that having chemistry community has been a huge help in helping me succeed. Some topics have been harder than others but having this resource always with me is a huge help.
- Sat Dec 01, 2018 11:09 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 5
- Views: 71
Re: Final
The last day of instruction will be Friday of week 10 but the last day of new material will be Wednesday week 10. Friday will be a review session during class like how it was for the midterm
- Sat Nov 24, 2018 12:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 3
- Replies: 10
- Views: 109
Re: Test 3
Brushing up on Outline 3 would't hurt since its on the test still.
- Tue Nov 20, 2018 3:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving Wednesday Class
- Replies: 19
- Views: 224
Re: Thanksgiving Wednesday Class
just came to say WOOOO NO CLASS WEDNESDAY!
- Sun Nov 18, 2018 3:11 pm
- Forum: Student Social/Study Group
- Topic: Studying for tests/midterm
- Replies: 18
- Views: 759
Re: Studying for tests/midterm
I challenge myself to do the harder homework problems and when I can't solve one I look at notes and online videos for that section
- Sun Nov 18, 2018 3:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Angular vs. Bent
- Replies: 7
- Views: 947
Re: Angular vs. Bent
They can be used in the same context, but specifically I believe bent is for when the general shape is distorted by lone pairs
- Sun Nov 18, 2018 3:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 3
- Replies: 19
- Views: 192
Re: Test 3
I think memorizing them would help especially knowing the bond angles for the each one.
- Sun Nov 11, 2018 5:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Due Week 7
- Replies: 10
- Views: 138
Re: Homework Due Week 7
Ya! We didn't really cover too much of outline 4 yet so Outline 3 stuff would be fine. Plus its always extra practice for the final
- Mon Nov 05, 2018 2:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
- Replies: 121
- Views: 4202
Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Can anyone help explain the process for 11a
Thank You!
Thank You!
- Sat Nov 03, 2018 4:25 pm
- Forum: Octet Exceptions
- Topic: Octet exceptions
- Replies: 8
- Views: 119
Octet exceptions
Hi,
Elements that are in period 3 and up can have expanded shells that hold more than 8 but will they always have more or when can they?
Elements that are in period 3 and up can have expanded shells that hold more than 8 but will they always have more or when can they?
- Sat Nov 03, 2018 4:04 pm
- Forum: *Particle in a Box
- Topic: Midterm
- Replies: 14
- Views: 400
Re: Midterm
Under what tab is last year's midterm in ccle?
- Tue Oct 23, 2018 6:09 pm
- Forum: Photoelectric Effect
- Topic: Question 1.B.15 7th
- Replies: 2
- Views: 67
Question 1.B.15 7th
Can someone help me with part A. Its given "the velocity of an electron is emitted from a metal surface by a photon is 3.6 x 10^3 km * s^-1 and are trying to find the wavelength of the ejected electron" Im having a hard time figuring out what equations to use or the steps to solving it. Th...
- Fri Oct 19, 2018 4:43 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 113
Re: Rydberg Equation
Thank you!! These were extremely helpful clarifying!
- Fri Oct 19, 2018 4:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community Due Date
- Replies: 6
- Views: 109
Re: Chem Community Due Date
I've heard many days but I'm sticking to Sunday which I heard the most. So long as you do 3 a week you should be fine :)
- Fri Oct 19, 2018 12:21 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 113
Rydberg Equation
Can someone explain when I should use the equation v = R * ( 1/n1^2 - 1/n2^2) and how does this relate to energy and the atomic spectra
- Fri Oct 12, 2018 9:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 86
- Views: 25179
Re: Advice from a Medical Student [ENDORSED]
This is some reassuring stuff, Thanks!
- Fri Oct 12, 2018 8:52 pm
- Forum: DeBroglie Equation
- Topic: Equations
- Replies: 9
- Views: 67
Re: Equations
We'll be given one form of equations so you'll need to be able to switch it up for what you need. We'll also have all the constants like c h R and a periodic table
- Fri Oct 12, 2018 8:41 pm
- Forum: Properties of Light
- Topic: question from class today
- Replies: 3
- Views: 22
Re: question from class today
The units of the numerator are J *S which is (kg*m^2*S^-2) *S
The denominator for it is (kg)*(m*S^-1) If you move the s^-1 to the numerator (1/s^-1 = s^1/1) the you get s^2 *s^-2 which will cancel the seconds and the kilograms
The denominator for it is (kg)*(m*S^-1) If you move the s^-1 to the numerator (1/s^-1 = s^1/1) the you get s^2 *s^-2 which will cancel the seconds and the kilograms
- Sat Oct 06, 2018 3:45 pm
- Forum: SI Units, Unit Conversions
- Topic: Modules?
- Replies: 8
- Views: 85
Modules?
Is there a specific due date for the first 4 modules or are they just help for our test.
- Sat Oct 06, 2018 3:14 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemistry Community Points
- Replies: 3
- Views: 45
Re: Chemistry Community Points
I believe that those would count since the first turn in isn't until Sunday so everything before that should count.
- Sat Oct 06, 2018 2:50 pm
- Forum: Significant Figures
- Topic: Sig Figs: Addition and Subtraction
- Replies: 3
- Views: 99
Re: Sig Figs: Addition and Subtraction
Addition and subtraction takes the Least significant figures after the decimal point. In this case, I think that one of the reasons is that you can't accurately say that the answer is 123456.608 because the .6 means that you estimated the measurement to .5 through .7 (or +/- .1). So if you keep the ...