Hi,
Is the rate-determining step the same as the slow step? Does this reaction ultimately define our rate?
Search found 105 matches
- Wed Mar 11, 2020 5:21 pm
- Forum: General Rate Laws
- Topic: Rate Determining Step
- Replies: 5
- Views: 336
- Wed Mar 11, 2020 5:18 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Pre-Equilibrium Approach
- Replies: 2
- Views: 245
Pre-Equilibrium Approach
Hello,
Can someone clarify the ideas behind the pre-equilibrium approach and explain when it is necessary to use this method? Thanks.
Can someone clarify the ideas behind the pre-equilibrium approach and explain when it is necessary to use this method? Thanks.
- Wed Mar 11, 2020 5:16 pm
- Forum: General Rate Laws
- Topic: Fast and Slow Step Reactions
- Replies: 5
- Views: 409
Fast and Slow Step Reactions
Hello,
What is the difference between a fast and slow step reaction? What does this information tell us with regard to solving problems?
What is the difference between a fast and slow step reaction? What does this information tell us with regard to solving problems?
- Wed Mar 11, 2020 5:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 3
- Views: 239
Test 2
Hello,
Does anybody know if Test 2 will become available for pick up anytime soon?
Does anybody know if Test 2 will become available for pick up anytime soon?
- Wed Mar 11, 2020 12:55 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts vs. Intermediates
- Replies: 8
- Views: 845
Re: Catalysts vs. Intermediates
An intermediate is produced in the first step then later consumed in the second step while the catalyst is consumed in the first step then produced in the second.
- Tue Mar 03, 2020 5:40 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst Equation
- Replies: 3
- Views: 353
Re: Nernst Equation
Letty Liu 2C wrote:I think it depends on what information you're given, so what you're working with. I believe there is only two versions of the Nernst equation though: one with lnQ and one with logQ.
Got it! But when do we use lnQ rather than logQ and vice versa?
- Tue Mar 03, 2020 5:39 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6N.15
- Replies: 2
- Views: 247
6N.15
I have a question about the following problem: Calculate the potential of a cell constructed with two nickel electrodes. The electrolyte in one compartment is 1.0 M Ni(NO3)2(aq). In the other compartment, NaOH has been added to a Ni(NO3)2 solution until the pH 5 11.0 at 298 K. See Table 6I.1. How do...
- Tue Mar 03, 2020 5:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Platinum and Granite
- Replies: 4
- Views: 333
Re: Platinum and Granite
Qiu Ya Wu 4I wrote:We use platinum and graphite as the electrode in our cell diagrams when there are no conducting solids present for the given half-reaction.
But what is the difference between the two? How do you know when to use one over the other?
- Tue Mar 03, 2020 5:02 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst Equation
- Replies: 3
- Views: 353
Nernst Equation
I've seen the different versions of the Nernst equation but when do we know whether to apply one of the other?
- Tue Mar 03, 2020 5:01 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Platinum and Granite
- Replies: 4
- Views: 333
Platinum and Granite
When do we know to use Pt(s) or C(gr) as our solid in cell diagrams?
- Fri Feb 28, 2020 11:13 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Spontaneity
- Replies: 12
- Views: 880
Re: Spontaneity
positive cell potential (-E) = negative delta G = spontaneous
negative cell potential (+E) = positive delta G = nonspontaneous
negative cell potential (+E) = positive delta G = nonspontaneous
- Fri Feb 28, 2020 11:11 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: platinum electrode
- Replies: 2
- Views: 215
Re: platinum electrode
The absence of a solid in your reaction would require the use of platinum as an electrode. As mentioned above, the fact that it is a good conductor will prevent it from interfering with the reaction.
- Fri Feb 28, 2020 11:07 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2
- Replies: 19
- Views: 896
Test 2
Will Test 2 have any overlapping topics from the midterm? Or will it only cover topics from the midterm up until now?
- Fri Feb 28, 2020 11:06 pm
- Forum: Balancing Redox Reactions
- Topic: Cell Diagrams
- Replies: 14
- Views: 937
Cell Diagrams
Does it matter which side you place the reduced reaction and the oxidized reaction? I've come across multiple sources that switch the orientation of the anode and cathodes so I could use some clarification on that. Thanks!
- Fri Feb 28, 2020 10:07 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic and Basic solutions
- Replies: 11
- Views: 674
Re: Acidic and Basic solutions
The procedure is the same but the basic solution requires you to use OH- instead of H+
- Sun Feb 23, 2020 10:38 am
- Forum: Balancing Redox Reactions
- Topic: Cell Diagrams
- Replies: 6
- Views: 350
Re: Cell Diagrams
My TA was informing us that the standard order for the elements in the cell diagram goes as following: solid|gas|aqueous || aqueous|gas|solid But it would be difficult to establish their phase accordingly. The question should provide you with any information you need while keeping in mind that one l...
- Sun Feb 23, 2020 12:38 am
- Forum: General Science Questions
- Topic: Content on Test 2
- Replies: 10
- Views: 658
Re: Content on Test 2
According to Lavelle's website, Test 2 will cover the 2nd page of Thermodynamics (see Outline) and Electrochemistry
- Sun Feb 23, 2020 12:24 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Using Pt
- Replies: 7
- Views: 433
Re: Using Pt
You can use Pt (s) if there is an absence of a solid in a redox reaction; because it is an inert conductor, it will allow for the transfer of electrons without interfering with the reaction itself
- Sun Feb 23, 2020 12:19 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Determining if a cell reaction is spontaneuous
- Replies: 5
- Views: 397
Re: Determining if a cell reaction is spontaneuous
A positive cell potential (E) will result in a negative delta G (via the equation delta G = -nFE), thus creating a spontaneous reaction. Similarly, a negative cell potential will result in a positive delta G, creating a nonspontaneous reaction
- Sun Feb 23, 2020 12:08 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 1
- Views: 209
Salt Bridge
Hello,
I just need clarification on the function of the salt bridge. Is its purpose to neutralize the charge build-up within the galvanic cell?
I just need clarification on the function of the salt bridge. Is its purpose to neutralize the charge build-up within the galvanic cell?
- Thu Feb 13, 2020 12:00 pm
- Forum: General Science Questions
- Topic: 50 post grade
- Replies: 25
- Views: 1743
Re: 50 post grade
It's entirely up to the TA- some will require you to submit 5 posts per week while others are fine with a total of 50 posts by the end of the quarter
- Thu Feb 13, 2020 11:56 am
- Forum: Student Social/Study Group
- Topic: Midterm
- Replies: 8
- Views: 661
Re: Midterm
My TA told us that 4I.9 was the homework question used on that exam
- Thu Feb 13, 2020 9:28 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Significance of open, closed, isolated
- Replies: 22
- Views: 1049
Re: Significance of open, closed, isolated
The status of the system helps you recognize the presence/absence of exchange in energy and matter, thus allowing you to understand the relationship between the system and its surroundings (and helps you solve the problems given).
- Thu Feb 13, 2020 9:26 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: units for heat capacity
- Replies: 2
- Views: 342
Re: units for heat capacity
As mentioned above, the units for heat capacity should be Joules/Celcius (J/°C) but if given kilojoules (kJ), this should be an acceptable answer as well unless the question specifically asks for joules, in which you would have to convert from kilojoules to joules.
- Thu Feb 13, 2020 9:23 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: change in Kc
- Replies: 5
- Views: 389
Re: change in Kc
If you were to reverse a reaction, the value for the constant will be the inverse (1/Kc) whereas if you multiply the reaction by some constant, the value of Kc will have to be raised by the same value (Kc^x).
- Fri Feb 07, 2020 4:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 1 Distribution
- Replies: 9
- Views: 302
Re: Test 1 Distribution
As everyone else has mentioned, there is no score distribution but you should ask your TA about your class average.
- Fri Feb 07, 2020 4:14 pm
- Forum: Student Social/Study Group
- Topic: Any Worksheets from UA/TA/etc?
- Replies: 14
- Views: 611
Re: Any Worksheets from UA/TA/etc?
You can check out Lyndon's review worksheet which will be posted tonight around 7 pm. He will be hosting a review session to go over the problems on Sunday.
- Fri Feb 07, 2020 4:13 pm
- Forum: General Science Questions
- Topic: Midterms
- Replies: 22
- Views: 871
Re: Midterms
Yes, the midterm will be cumulative, covering the topics from equilibrium to thermodynamics
- Fri Feb 07, 2020 3:55 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: biological examples
- Replies: 7
- Views: 274
Re: biological examples
Are these biological examples going to be on the midterm?
- Fri Feb 07, 2020 3:46 pm
- Forum: Calculating Work of Expansion
- Topic: Isothermal
- Replies: 17
- Views: 698
Re: Isothermal
Isothermal means there is a constant temperature present in the system, therefore, the most ideal equations to use would be the ones that include a change in volume or pressure
- Fri Jan 31, 2020 2:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Math Resources
- Replies: 8
- Views: 232
Math Resources
Hello,
In today's lecture, Lavelle mentioned having extra resources to review on calculus. Can these be found on his website?
Thanks!
In today's lecture, Lavelle mentioned having extra resources to review on calculus. Can these be found on his website?
Thanks!
- Fri Jan 31, 2020 2:01 pm
- Forum: General Science Questions
- Topic: Extra Credit
- Replies: 19
- Views: 747
Re: Extra Credit
Unfortunately, there are no extra credit opportunities for this class. Make sure to try your best and study hard!
- Fri Jan 31, 2020 1:58 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: State Functions
- Replies: 6
- Views: 159
Re: State Functions
Unlike heat and work functions, they are dependent on the path taken in order to reach the endpoint
- Fri Jan 31, 2020 1:54 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: hess's law
- Replies: 13
- Views: 308
Re: hess's law
Yes, they must be on opposite sides and they have to be balanced in order to cancel them out
- Fri Jan 31, 2020 1:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 8
- Views: 312
Re: Midterm
Based off of Lavelle's class announcements, I believe it will cover all the topics we have discussed until now, finishing with thermodynamics. You can use the class outlines to guide your studying as Lavelle has mentioned that the material is based on the objectives
- Fri Jan 24, 2020 5:15 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14A Final Exam
- Replies: 1
- Views: 122
Chem 14A Final Exam
Does anyone know if the final exams are available after Week 3? If so, where can we find them?
- Thu Jan 23, 2020 10:58 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Best Way To Study?
- Replies: 13
- Views: 588
Re: Best Way To Study?
I would definitely recommend the UA sessions. For extra practice and better understanding, I would recommend "The Organic Chemistry Tutor" on Youtube because he explains concepts in addition to working through examples. Overall, try to stay on track with the homework and understand them as...
- Thu Jan 23, 2020 9:55 pm
- Forum: Phase Changes & Related Calculations
- Topic: Autoprotolysis
- Replies: 15
- Views: 740
Re: Autoprotolysis
It is the proton transfer between two of the same molecules
- Tue Jan 21, 2020 8:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Practice Worksheet for Test 1
- Replies: 1
- Views: 197
Practice Worksheet for Test 1
Can anyone explain how they solved the following question (#7 from the UA Practice Exam Worksheet)? Thanks!
"A basic aqueous reaction initially had 0.057 M NH3. At equilibrium the concentration of hydroxides was 1.0x10^-3. Write out the equation and find the percent protonated."
"A basic aqueous reaction initially had 0.057 M NH3. At equilibrium the concentration of hydroxides was 1.0x10^-3. Write out the equation and find the percent protonated."
- Tue Jan 21, 2020 8:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Worksheet Practice for Test 1
- Replies: 3
- Views: 244
Re: Worksheet Practice for Test 1
You would set up an ice table. Initial concentrations: 1 for H2, 2 for Cl2, and 0 for HCl. We don't know how much the change is, so we represent this with -x, -x, and +2x, respectively. Therefore, the expressions for the equilibrium are: H2 = 1-x, Cl2 = 2-x, and HCl = 4x^2. Write the expression for...
- Tue Jan 21, 2020 8:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 1 Study Guide/Worksheet
- Replies: 5
- Views: 804
Re: Test 1 Study Guide/Worksheet
Can someone explain their process for #6? Thanks!
- Wed Jan 15, 2020 9:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use K and Kp
- Replies: 12
- Views: 371
Re: When to use K and Kp
If the problem doesn't specify, either should be fine to use. Although, if you are given concentrations then you are likely to use Kc rather than Kp, or if the problem mentions a gas, you would use Kp for partial pressure
- Wed Jan 15, 2020 9:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Study Guide Test One
- Replies: 17
- Views: 611
Re: Study Guide Test One
I don't believe so but it's useful to rely on the learning outcomes and base your studying on the areas you need the most practice on
- Wed Jan 15, 2020 9:15 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Factors
- Replies: 7
- Views: 224
Factors
Is temperature the only factor that influences K? Also, which factors influence the reaction quotient?
- Wed Jan 15, 2020 9:12 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: biological examples
- Replies: 2
- Views: 168
Re: biological examples
Just curious, do you know if we'll need to know certain biological examples for future exams?
- Wed Jan 15, 2020 9:05 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE Tables
- Replies: 4
- Views: 173
ICE Tables
I'm still a bit confused when it comes to ICE tables. What are certain indicators of a problem that lets us know we'll need an ICE table to solve it?
- Thu Jan 09, 2020 9:17 pm
- Forum: Student Social/Study Group
- Topic: Homework for Week 1
- Replies: 6
- Views: 360
Homework for Week 1
Is the homework for this week due tomorrow (Friday) in lecture or in discussion next week?
- Thu Jan 09, 2020 9:13 pm
- Forum: Ideal Gases
- Topic: R in PV=nRT
- Replies: 34
- Views: 5870
Re: R in PV=nRT
R is the gas constant but it can use different units such as torr, atm, or bar
- Thu Jan 09, 2020 8:54 pm
- Forum: Ideal Gases
- Topic: converting Kc to Kp
- Replies: 13
- Views: 396
Re: converting Kc to Kp
Megan Kirschner wrote:What exactly is the difference between Kc and Kp? I know (or think) they are equilibria constants but what do they individually represent?
Kc is used for the concentration of aqueous solutions and gases while Kp is for the partial pressures of gases
- Thu Jan 09, 2020 8:41 pm
- Forum: Ideal Gases
- Topic: Reaction Quotient (Q)
- Replies: 8
- Views: 288
Reaction Quotient (Q)
Can someone explain the concept behind Q? When is it essential?
- Thu Jan 09, 2020 8:18 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc and Kp
- Replies: 4
- Views: 166
Kc and Kp
Can someone clarify the following for me? Are these the correct uses for Kc and Kp?
Kc = concentration of gases
Kp = partial pressures
Kc = concentration of gases
Kp = partial pressures
- Thu Jan 09, 2020 8:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units for K
- Replies: 10
- Views: 240
Units for K
Why doesn't K have any units?
- Fri Dec 06, 2019 1:12 am
- Forum: Calculating the pH of Salt Solutions
- Topic: Wednesday Lecture 12/4
- Replies: 4
- Views: 359
Re: Wednesday Lecture 12/4
Wednesday's lecture placed emphasis on Chem 14B and introduced us to the topics we will learn in that class. I don't believe we have to know anything in particular from that lecture for the final
- Fri Dec 06, 2019 1:10 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shape
- Replies: 1
- Views: 135
Shape
How would you figure out the shape of the following coordinate compound?
[Cr(NH3)3Cl3]
[Cr(NH3)3Cl3]
- Thu Dec 05, 2019 3:06 pm
- Forum: Biological Examples
- Topic: Biological questions on the final
- Replies: 5
- Views: 461
Re: Biological questions on the final
I would suggest looking at the examples mentioned above plus acid rain (not for coordination compounds but it is a real-life example that has come up throughout UA worksheets)
- Thu Dec 05, 2019 3:03 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: -ate
- Replies: 11
- Views: 686
Re: -ate
-ate is added to the end of the metal name when there is an overall negative charge to the complex
- Thu Dec 05, 2019 2:59 pm
- Forum: Student Social/Study Group
- Topic: Finals Preparation
- Replies: 7
- Views: 572
Re: Finals Preparation
Avoiding any last-minute cramming and getting a good night's sleep is always a good idea before exams
- Thu Dec 05, 2019 2:57 pm
- Forum: Student Social/Study Group
- Topic: Grading
- Replies: 3
- Views: 305
Grading
The syllabus states, "50% or higher is required to pass with a C- or higher". Does this mean you need 250 out of the 500 points to pass the class with a C-?
- Tue Nov 26, 2019 11:30 am
- Forum: Bronsted Acids & Bases
- Topic: Lewis Structures of Acid/Base reactions
- Replies: 3
- Views: 153
Re: Lewis Structures of Acid/Base reactions
I don't believe it will be on the test but Dr.Lavelle draws the structures in class in order to help us better understand the concept. Drawing the Lewis structures can only benefit you but it is not required
- Tue Nov 26, 2019 11:26 am
- Forum: Sigma & Pi Bonds
- Topic: Molecular Shape
- Replies: 11
- Views: 684
Re: Molecular Shape
They do not influence molecular structure because each bond is considered to be one region of electron density, despite the single/double/triple bonds that can be present
- Tue Nov 26, 2019 11:23 am
- Forum: Naming
- Topic: -ate ending
- Replies: 8
- Views: 564
Re: -ate ending
If the complex is an anion/contains a negative charge, you at the -ate to the end of the transition metal
- Tue Nov 26, 2019 11:19 am
- Forum: Naming
- Topic: H2O vs OH2
- Replies: 3
- Views: 168
Re: H2O vs OH2
They are interchangeable terms but using one over the other is to indicate the presence of the lone pair on the oxygen. Usually, H2O is written on the left and OH2 is on the right in order to accommodate for the bond that exists between the lone pair of the oxygen and the ligand/central atom
- Tue Nov 26, 2019 11:15 am
- Forum: Dipole Moments
- Topic: Intermolecular force
- Replies: 5
- Views: 588
Re: Intermolecular force
Yes, that should be fine because it is true that the stronger an intermolecular force is, the more difficult it is to break the bond
- Sun Nov 24, 2019 11:04 pm
- Forum: Student Social/Study Group
- Topic: Any tips on how to catch up in this class?
- Replies: 16
- Views: 918
Re: Any tips on how to catch up in this class?
I'd recommend studying with others, attending the UA workshops, and watching YouTube videos that cover the general ideas on the topics we are studying. It is pretty easy to get lost in the class but reserving time to review past material is essential for catching up in addition to making use of thes...
- Sat Nov 23, 2019 4:32 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds
- Replies: 6
- Views: 428
Re: Sigma and Pi Bonds
If the orbitals that form sigma bonds overlap more than the pi bonds, how is it that sigma bonds can rotate and have more flexibility than the pi bonds?
- Sat Nov 23, 2019 4:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving Break
- Replies: 4
- Views: 431
Re: Thanksgiving Break
Lavelle has a post on Chemistry Community (see link below) where he states that we can turn in the homework for Week 9 and 10 during Week 10
viewtopic.php?f=157&t=52609
viewtopic.php?f=157&t=52609
- Sat Nov 23, 2019 4:26 pm
- Forum: General Science Questions
- Topic: Final
- Replies: 10
- Views: 659
Re: Final
The final is cumulative so it will be covering all the topics from weeks 1-10
- Sat Nov 23, 2019 4:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lecture on 11/27
- Replies: 4
- Views: 324
Lecture on 11/27
Will we still have lecture on Wednesday, November 27th or will it be canceled due to Thanksgiving break? Thanks
- Sun Nov 17, 2019 2:15 pm
- Forum: Hybridization
- Topic: Test?
- Replies: 6
- Views: 361
Re: Test?
Lavelle said during Friday's lecture that hybridization will not be included on the test. The cutoff will be at sigma bonds which will be the first slide on Monday's lecture
- Sun Nov 17, 2019 1:28 pm
- Forum: General Science Questions
- Topic: Test 2
- Replies: 7
- Views: 361
Re: Test 2
The test will cover material after the midterm which has been very conceptual thus far. I don't think certain calculations are required but I would suggest checking in with the TAs
- Sun Nov 17, 2019 1:23 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling Points
- Replies: 7
- Views: 538
Boiling Points
What is the relationship between boiling points and the type of intermolecular force? Are boiling points dependent on the strength of the force? Thanks!
- Sun Nov 17, 2019 1:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Interactions
- Replies: 3
- Views: 111
Interactions
Out of the following interactions, is this the correct order from strongest to weakest bond?
ion-dipole > hydrogen bonds > dipole-dipole > Van Der Waals
Also, is Van Der Waals the same as London Dispersing forces? If not, what is their difference? Thanks!
ion-dipole > hydrogen bonds > dipole-dipole > Van Der Waals
Also, is Van Der Waals the same as London Dispersing forces? If not, what is their difference? Thanks!
- Sun Nov 17, 2019 12:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Wed before Thanksgiving
- Replies: 3
- Views: 155
Re: Wed before Thanksgiving
As far as everyone knows, we will have a lecture on Wednesday before Thanksgiving. You can always double-check with the TAs or with Lavelle beforehand though
- Thu Nov 07, 2019 10:10 pm
- Forum: Bond Lengths & Energies
- Topic: Week 7 Homework
- Replies: 15
- Views: 805
Week 7 Homework
For next week's homework are we turning in questions from the Chemical Bonds section or do we move onto Molecular Shape and Structure?
- Thu Nov 07, 2019 1:21 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Shortcut for Formal Charge
- Replies: 19
- Views: 1597
Re: Shortcut for Formal Charge
(# of valence electrons) - (# of electrons + # of bonds) = formal charge
or if you want an even simpler way of thinking about it: (# of valence electrons) - (# of dots + # of lines)
or if you want an even simpler way of thinking about it: (# of valence electrons) - (# of dots + # of lines)
- Thu Nov 07, 2019 1:18 pm
- Forum: Lewis Structures
- Topic: When to draw Resonance Structures
- Replies: 14
- Views: 930
Re: When to draw Resonance Structures
It's best to always draw resonance structures if the molecule has them. It demonstrates your understanding and it's just safe to have even if you aren't being directly asked to provide them
- Thu Nov 07, 2019 1:17 pm
- Forum: Ionic & Covalent Bonds
- Topic: Solubility
- Replies: 3
- Views: 215
Solubility
How do solubility and ionic/covalent character relate to one another? Is ionic character more soluble and covalent character less soluble?
- Thu Nov 07, 2019 1:14 pm
- Forum: Student Social/Study Group
- Topic: Class Grading
- Replies: 44
- Views: 3517
Re: Class Grading
Yes, that's correct. The grades will be dependent on the number of points and the cutoffs made by Dr.Lavelle with regards to the class average
- Thu Nov 07, 2019 1:10 pm
- Forum: Bond Lengths & Energies
- Topic: Bond lengths in resonance structures
- Replies: 2
- Views: 187
Re: Bond lengths in resonance structures
The bond lengths in resonance structures will be an average of all the present bonds; this is due to the creation of a resonance hybrid which creates another molecular structure from all the other existing resonance structures
- Thu Oct 31, 2019 11:39 am
- Forum: Administrative Questions and Class Announcements
- Topic: Study Tips!
- Replies: 7
- Views: 295
Re: Study Tips!
Watching YouTube videos and taking notes on them has been very resourceful for me. It helps me gain a better understanding of the concepts for equations and the main topics of our classes.
- Thu Oct 31, 2019 11:33 am
- Forum: Photoelectric Effect
- Topic: Threshold Energy
- Replies: 5
- Views: 320
Threshold Energy
Hello, I just need clarification on threshold energy. I know the threshold energy is the energy needed in order to eject electrons from a metal surface but in terms of the equation, is it represented by the work function? Thanks!
- Thu Oct 31, 2019 11:24 am
- Forum: DeBroglie Equation
- Topic: Confused about equations
- Replies: 7
- Views: 400
Confused about equations
Hello,
This is a dumb question but I need clarification as to when you use certain equations since I always seem to mix them up. For instance, what kinds of problems indicate the use of the de Broglie equation (λ = h/mv) in contrast to the equations for wavelength (c= λv) and energy (E=hv)?
Thanks!
This is a dumb question but I need clarification as to when you use certain equations since I always seem to mix them up. For instance, what kinds of problems indicate the use of the de Broglie equation (λ = h/mv) in contrast to the equations for wavelength (c= λv) and energy (E=hv)?
Thanks!
- Thu Oct 31, 2019 11:14 am
- Forum: Student Social/Study Group
- Topic: Study Tips
- Replies: 58
- Views: 4317
Re: Study Tips
Personally I have found YouTube to be very resourceful because the videos provide extra material in addition to lectures which helps me understand the concepts better and relate them to the practice problems we go over. I would also suggest taking notes while you're watching the video because it's h...
- Thu Oct 31, 2019 11:06 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Practice Question for Midterm
- Replies: 2
- Views: 324
Re: Practice Question for Midterm
Thank you so much!! That makes more sense. The equation editor is really useful in making sense of the math so thanks for that as well.
- Wed Oct 30, 2019 1:58 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Practice Question for Midterm
- Replies: 2
- Views: 324
Practice Question for Midterm
Hello, could someone explain how to solve for this question? Thanks! "Potassium permanganate, KMnO4, is an inorganic chemical compound used for cleaning wounds. 5.00 g of KMnO4 is dissolved in a 150.00 mL flask of water. If 20.00 mL of this solution is removed and placed in a new 2nd 250.00 mL ...
- Thu Oct 24, 2019 5:26 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Noble Gas Configuration
- Replies: 10
- Views: 860
Re: Noble Gas Configuration
There's no specific rule as to when you must use the noble gas configuration over the complete electron configuration. My TA said it is much simpler to use the noble gas configuration but to be careful on exams when you are asked to provide the entire electron configuration of an element
- Thu Oct 24, 2019 5:18 pm
- Forum: Trends in The Periodic Table
- Topic: Periodic Trend Exceptions
- Replies: 7
- Views: 230
Re: Periodic Trend Exceptions
I know there is a trend for valence electrons which is to look at the column number to determine the number of valence electrons found in a certain element. Although, this only applies to the s and p blocks.
- Thu Oct 24, 2019 5:03 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg equation [ENDORSED]
- Replies: 73
- Views: 8687
Re: Rydberg equation [ENDORSED]
In what kinds of scenarios or questions would we need to use the Rydberg equation?
- Thu Oct 24, 2019 12:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Cation
- Replies: 23
- Views: 1626
Re: Cation
Cations are atoms with a positive charge (+) while anions are atoms with a negative charge (-); this is due to the loss or gain of electrons. They are important because they are essential to the formation of ionic bonds, bonds in which electrons are lost or gained in order to reach a more stable sta...
- Thu Oct 24, 2019 11:00 am
- Forum: Properties of Light
- Topic: Midterm
- Replies: 4
- Views: 294
Re: Midterm
He did mention that he will have multiple review sessions (spread out through his lectures I believe?) but primarily, he mentioned having a large review session on the Saturday or Sunday before the midterm- his only concern is obtaining a large lecture room so that many people can attend. He also me...
- Wed Oct 16, 2019 4:33 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Tutoring? [ENDORSED]
- Replies: 121
- Views: 240623
Re: Tutoring? [ENDORSED]
I would definitely recommend signing up for AAP's peer learning sessions as well as joining study groups with other classmates. There are many resources out there in addition to tutors. Peer learning sessions offer many study sessions so they are flexible with your schedules- they also do midterm an...
- Wed Oct 16, 2019 4:21 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Difference Between Ground and Excited States
- Replies: 3
- Views: 142
Re: Difference Between Ground and Excited States
An electron is at its excited state whenever its energy level is higher than its corresponding ground state. During ground state, its electron configuration is at default whereas, during the excited state, it will jump into a high orbital
- Wed Oct 16, 2019 4:16 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 2 Homework Problems [ENDORSED]
- Replies: 67
- Views: 7209
Re: Week 2 Homework Problems [ENDORSED]
RichBollini3C wrote:Diana Chavez-Carrillo 3J wrote:Are the TA's grading our homework based on completion or correctness?
I believe they are grading based on correctness.
Do you know if all the TAs grade based on correctness or does it vary from TA to TA?
- Wed Oct 16, 2019 4:13 pm
- Forum: *Shrodinger Equation
- Topic: Equations for Quantum Topics
- Replies: 3
- Views: 125
Equations for Quantum Topics
Hello, I'm just looking for clarification on the equations that are currently being used in the material we are studying right now. So far, Lavelle has gone over three main equations: the de Broglie equation, Schrodinger's equation, and Heisenberg's indeterminacy equation. Are there any more essenti...
- Wed Oct 16, 2019 4:06 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What are subshells
- Replies: 4
- Views: 238
Re: What are subshells
The letter, s, p, d, and f, refer to subshells which are orbitals that correspond to already existing orbitals. Each of the subshells has its own orbitals as well. For example, the s subshell has 1, the p subshell has 3, and so forth.
- Fri Oct 11, 2019 11:28 am
- Forum: Student Social/Study Group
- Topic: Peer Learning Sessions
- Replies: 3
- Views: 211
Re: Peer Learning Sessions
Anyone enrolled in the course can attend- you just show up to the session!
- Fri Oct 11, 2019 11:26 am
- Forum: Student Social/Study Group
- Topic: Weekly Posts
- Replies: 6
- Views: 259
Weekly Posts
Hello- are our five weekly posts due by Friday or Sunday? I know we have to post five comments by the end of the week but I was wondering if there was a definite deadline. Thanks!
- Fri Oct 11, 2019 11:11 am
- Forum: Administrative Questions and Class Announcements
- Topic: Weekly Posts
- Replies: 4
- Views: 229
Re: Weekly Posts
I don't believe any comments from the previous week carries onto the next- this is to encourage students to interact weekly. I would suggest making five posts per week just to be safe.
- Fri Oct 11, 2019 11:08 am
- Forum: Administrative Questions and Class Announcements
- Topic: Posting
- Replies: 3
- Views: 240
Re: Posting
You can go to the board index and scroll down until you find the forums. From there, you open the forum that corresponding to the topic of your choosing. After you've opened it, you can click on "New Topic" in order to make a post. Hope this helps!
- Fri Oct 11, 2019 11:00 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Theoretical vs. Actual Yield
- Replies: 38
- Views: 13875
Re: Theoretical vs. Actual Yield
Like any experiment, there are always side reactions that can occur such as loss of heat, impurities (product sticks to the side of the beaker), or human error (incorrect measurements of reactants). Taking these things into account, the actual yield is going to be less than the theoretical yield bec...