Search found 103 matches
- Sat Mar 14, 2020 10:35 pm
- Forum: Balancing Redox Reactions
- Topic: cathode vs anode
- Replies: 11
- Views: 848
Re: cathode vs anode
If you're given the cell diagram, the cathode is usually on the right of the diagram and the anode on the left.
- Sat Mar 14, 2020 10:26 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Problems
- Replies: 3
- Views: 343
Re: Problems
Jessica Chen 2C wrote:Thanks for the response! Could someone summarize what knowing the type of system would tell you for each system? Like if it’s an isolated system, do I know that a certain value would be 0 or something?
The change in entropy is greater than or equal to 0 in an isolated system.
- Sat Mar 14, 2020 10:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Time
- Replies: 13
- Views: 947
Re: Final Exam Time
I'm pretty sure that in case major technical difficulties occur, we can email Lavelle or our TAs just in case.
- Sat Mar 14, 2020 4:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grading Scale
- Replies: 16
- Views: 1105
Grading Scale
Does anyone know if he's using the same grading scale as last quarter for 14A?
- Sat Mar 14, 2020 4:07 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Return
- Replies: 20
- Views: 1226
Re: Test 2 Return
I'm not sure if it's for all TA's, but my TA had us pick our tests up in her mailbox. Maybe try emailing your TA to see if they're also willing to do that?
- Sat Mar 14, 2020 4:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constants
- Replies: 15
- Views: 952
Re: Equilibrium Constants
Julia Holsinger_1A wrote:When the equilibrium constant K is larger than 10^3 does the reaction favor the products or the reactants?
When it's larger it favors the products.
- Sat Mar 14, 2020 4:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constants
- Replies: 15
- Views: 952
Re: Equilibrium Constants
Yes, definitely. Always check in case there's a typo or possibly a little "trick".
- Sat Mar 14, 2020 4:03 pm
- Forum: Balancing Redox Reactions
- Topic: OH vs H
- Replies: 12
- Views: 908
Re: OH vs H
No, it's never used for balancing in an acidic solution.
- Fri Mar 13, 2020 10:02 pm
- Forum: *Nucleophiles
- Topic: FInal
- Replies: 11
- Views: 1746
Re: FInal
I think it's better to know about these topics in depth, just to get a better understanding along with what Lavelle has gone over throughout the quarter.
- Fri Mar 13, 2020 10:00 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation number
- Replies: 12
- Views: 1241
Re: Oxidation number
It relates to when you balance a redox equation, since they relate to charge. If an oxidation number/charge becomes more negative/smaller, then it means that there is a gain of electrons (Fe +3 ----> Fe +2). If it becomes more positive/larger, then there's a loss of electrons (Cr +3 ----> Cr +6). Re...
- Fri Mar 13, 2020 9:46 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Collision theory
- Replies: 2
- Views: 184
Collision theory
Does anyone know if collision theory will be emphasized a lot in the final?
- Thu Mar 12, 2020 8:29 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Review Question #2
- Replies: 2
- Views: 298
Review Question #2
If you were to increase the volume of a reaction, would it yield more products?
- Thu Mar 12, 2020 8:25 am
- Forum: Administrative Questions and Class Announcements
- Topic: "Open Book" Final?
- Replies: 30
- Views: 2124
Re: "Open Book" Final?
I think that lecture notes and the textbook are fine. I don't think chemistry community is allowed though.
- Wed Mar 11, 2020 2:07 pm
- Forum: General Science Questions
- Topic: Chemistry Final
- Replies: 16
- Views: 1234
Re: Chemistry Final
I don't think that it's likely due to the formats of past finals/midterms. Since this situation different, it most likely a mix.
- Wed Mar 11, 2020 12:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Review Packet
- Replies: 5
- Views: 458
Review Packet
Does anyone know if we'll get a review packet to work on even though reviews have been cancelled?
- Mon Mar 09, 2020 5:36 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 21
- Views: 1439
Re: Final
As of now, I'm pretty sure we're taking our finals in the locations on the review sheet Lavelle gave us.
- Mon Mar 09, 2020 5:27 pm
- Forum: General Rate Laws
- Topic: 7A 15
- Replies: 4
- Views: 328
Re: 7A 15
It's independent if you see that the changes in concentration don't affect the rate. If you compare Experiments 1 and 4, you can see that only C changes in concentration, but the rate stays the same.
- Mon Mar 09, 2020 5:21 pm
- Forum: First Order Reactions
- Topic: Half Life Equations
- Replies: 10
- Views: 618
Re: Half Life Equations
I'm pretty sure they were written on our tests last week so it's likely that they'll be provided. It doesn't hurt to memorize them though.
- Sun Mar 08, 2020 10:24 pm
- Forum: General Rate Laws
- Topic: 7A.9
- Replies: 5
- Views: 375
Re: 7A.9
For this problem just use the first order equation, Rate=k[A]. Just find the concentration of N2O5 by converting the grams into moles, and then placing it over the amount in liters. Finally, all you have to do is multiply the k given with the concentration.
- Sun Mar 08, 2020 5:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 7
- Views: 464
Re: Cell Diagrams
You add platinum (s) or carbon (gr) when the anode and/or the cathode have no solid conductors in the cell diagram (they either have nonmetals or metals in an aqueous phase). As far as I know, platinum and carbon can be used interchangeably, but platinum is more common.
- Sun Mar 08, 2020 5:31 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 7A.15
- Replies: 5
- Views: 400
Re: 7A.15
In this case, since C is a zero order reaction (Rate=k), you won't really need to take C into account since its concentrations won't have any effect on the rate. Just solve for A and B as if C wasn't there.
- Sun Mar 08, 2020 5:26 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 7A.15
- Replies: 3
- Views: 300
Re: 7A.15
Why don't concentrations for zero order reactions matter? For zero order reactions, the differential rate late is just Rate=k. The concentrations aren't included in this calculation, so since C in this question is a zero order reaction, changing its concentration (like in Experiments 1 and 4) won't...
- Sun Mar 08, 2020 4:30 pm
- Forum: Zero Order Reactions
- Topic: 7A.17
- Replies: 1
- Views: 192
7A.17
Does anyone know why certain experiments are compared to each each to solve?
- Sun Mar 08, 2020 2:01 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding carbon (gr) to cell diagrams
- Replies: 4
- Views: 361
Adding carbon (gr) to cell diagrams
I know that adding carbon is not as common adding platinum, but when would you need to add carbon (gr).
- Sun Mar 08, 2020 1:56 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: When to add Platinum
- Replies: 8
- Views: 493
Re: When to add Platinum
I believe you add platinum to a cell diagram when the anode and/or the cathode need a solid conductor. How do we know/tell if the anode or cathode needs a solid conductor? We know we do based on the phases of the molecules. If it's just aqueous phases, then you'll definitely need one. Even in cases...
- Sun Mar 08, 2020 1:51 pm
- Forum: General Science Questions
- Topic: Review Packet
- Replies: 14
- Views: 1272
Review Packet
Does anyone know if we are getting another review packet and if so does anyone know when it will be posted? Are the review sessions up as well?
- Tue Mar 03, 2020 8:29 pm
- Forum: Balancing Redox Reactions
- Topic: 6K.3 part D
- Replies: 3
- Views: 256
6K.3 part D
Is there a specific reason why the reduction part is written as Cl2 + 2e- ---> 2Cl - instead of using Cl2 as written in the problem?
- Sun Mar 01, 2020 11:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: what to know for test 2
- Replies: 10
- Views: 621
Re: what to know for test 2
I remember hearing that Gibbs Free energy was going to be on it, and I think most of electrochemistry is fair game too.
- Sun Mar 01, 2020 10:57 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode and Cathode
- Replies: 8
- Views: 597
Re: Anode and Cathode
The anode is the part of the cell that performs oxidation, so the element/compound inside loses an electron. This electron transfers over to the cathode, which performs reduction and adds the electron to the corresponding element/compound inside. Just to add on: one way you can remember this is wit...
- Sun Mar 01, 2020 10:53 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: When to add Platinum
- Replies: 8
- Views: 493
Re: When to add Platinum
I believe you add platinum to a cell diagram when the anode and/or the cathode need a solid conductor.
- Sun Mar 01, 2020 10:32 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Reducing/oxidizing agent
- Replies: 8
- Views: 577
Re: Reducing/oxidizing agent
Since oxidation occurs when an ion loses electrons (ends up having a more positive charge), you have to figure out the charges between the reactants and the products side. Like in Example 6K.1 (page 538), the oxidation half reaction is between C2H2O4 and CO2, because C goes from having a charge of +...
- Sun Mar 01, 2020 9:52 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic and Basic Reactions
- Replies: 9
- Views: 523
Re: Acidic and Basic Reactions
H+ is added for balancing reactions in acidic solutions, and OH- is used for basic solutions. Just remember that in acidic solutions, only H+ is used for balancing H, while for basic solutions H2O is added to the side that needs H and add OH- to the other side of the reaction.
- Thu Feb 27, 2020 11:11 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding conductors to cell diagrams
- Replies: 1
- Views: 129
Adding conductors to cell diagrams
When do you add carbon (graphite) as a conductor instead of platinum?
- Sun Feb 23, 2020 9:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: l vs ll
- Replies: 5
- Views: 365
Re: l vs ll
The double lines just separate the oxidation half reaction and the reduction half reaction. The single line is just used to separate elements of different phases (gas/liquid/solid/aqueous solution) in a half reaction.
- Sun Feb 23, 2020 9:16 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation States
- Replies: 7
- Views: 419
Re: Oxidation States
There are some things to look out for when finding oxidation states: 1. The oxidation number for an atom in an elemental form is always 0 2.The oxidation number of of all Group 1A metals is +1, and Group 2A is +2, unless they are elemental. 3. Hydrogen is either +1 (when bonded to a nonmetal), or -1...
- Sun Feb 23, 2020 9:04 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Redox Equations
- Replies: 7
- Views: 480
Re: Balancing Redox Equations
You can tell by comparing the charges of the element as a reactant and as a product. The charges are either given directly in the chemical equation (like Fe +2) or are calculated (like with MnO4, which has an overall charge of -1, Mn is calculated to have a charge of +7 since the four oxygen atoms h...
- Sun Feb 23, 2020 8:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 5
- Views: 389
Re: Test 2
I'm pretty sure it extends into this week as well.
- Sun Feb 23, 2020 8:38 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing in a Basic Solution
- Replies: 3
- Views: 223
Balancing in a Basic Solution
Is there a reason why we balance a redox reaction with H2O and OH when it's a basic solution instead of just H2O and H?
- Sun Feb 16, 2020 10:54 pm
- Forum: General Science Questions
- Topic: Studying
- Replies: 67
- Views: 3966
Re: Studying
Study groups are also extremely helpful, as everyone can have different grasps on different topics.
- Sun Feb 16, 2020 10:52 pm
- Forum: General Science Questions
- Topic: homework for week 7
- Replies: 7
- Views: 487
Re: homework for week 7
I'm pretty sure we can still work on thermodynamics, specifically Focus 5G.
- Sun Feb 02, 2020 8:32 pm
- Forum: Calculating Work of Expansion
- Topic: Thermochemistry and thermodynamics
- Replies: 3
- Views: 125
Re: Thermochemistry and thermodynamics
I'm pretty sure you're not alone on this; I'm having a bit of trouble too. I know peer leaning sessions help immensely, as the mentors are able to explain things in more detail and you can work in a small group at a time. Chemistry Community is also a great place for questions, and never be afraid o...
- Sun Feb 02, 2020 8:26 pm
- Forum: General Science Questions
- Topic: Extra Credit
- Replies: 19
- Views: 838
Re: Extra Credit
He doesn't give any but if you are worried about grades you may be able to talk to him about it.
- Sun Feb 02, 2020 8:25 pm
- Forum: Student Social/Study Group
- Topic: Midterm study
- Replies: 8
- Views: 498
Re: Midterm study
For review sessions, just go to the ones you feel like you would need the most amount of help in. They are lots of them to help fit with everyone's schedule, so if there's a particular section you don't feel confident in, you can go to multiple of the same topic. I would highly recommend the review ...
- Thu Jan 23, 2020 12:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test 1
- Replies: 4
- Views: 210
Test 1
For those of you who have already taken the quiz, up to what subject do you recommend that we prepare for, and what topic should we put an emphasis on for studying?
- Thu Jan 23, 2020 12:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Best Way To Study?
- Replies: 13
- Views: 655
Re: Best Way To Study?
Doing all the homework problems does help in terms of practice. I also got a lot of help through peer learning sessions, as they were able to give a lot more practice and were able to clear up a lot of the material.
- Thu Jan 23, 2020 12:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6B.3
- Replies: 2
- Views: 119
6B.3
Does anyone know why we have to multiply the concentration by 2 for part C? The solution manual says to do that, but I'm not sure if that's correct.
- Sun Jan 19, 2020 11:45 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice Tables
- Replies: 4
- Views: 140
Re: Ice Tables
In some problems, I've seen that ICE tables are used to solve for the equilibrium concentrations/partial pressures of reactants and products.
- Sun Jan 19, 2020 11:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q
- Replies: 6
- Views: 368
Re: Q
K and Q are really similar when it comes to solving for them (they use the same formulas). Q however, can be solved during any point of a reaction, while K is only solved for at equilibrium.
- Sun Jan 12, 2020 8:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Types of Equilibrium Constants
- Replies: 7
- Views: 278
Re: Types of Equilibrium Constants
You can probably figure out which is going to be used if they use the terms "partial pressure" (which means that Kp will be used), or "concentration" (meaning Kc will be used). Kc is also used if the problem says that a certain amount of moles is mixed with a certain amount of so...
- Sun Jan 12, 2020 8:25 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 3
- Views: 113
Re: PV=nRT
The R is the gas constant, which is generally R = 8.314 J·K-1·mol-1. You can find it on the constants and equations sheet on the 14B website, along with its other conversions.
- Sun Jan 12, 2020 8:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Studying tips
- Replies: 10
- Views: 506
Re: Studying tips
Definitely do more than the required amount of homework assignments to get a broader sense of the topic, peer learning sessions, and studying with friends helps a lot. There are plenty of office hours so don't be afraid to go there, especially since we are able to go to all TA hours. Another thing t...
- Sun Jan 12, 2020 8:06 pm
- Forum: Ideal Gases
- Topic: Le Chatelier's Principle
- Replies: 7
- Views: 473
Re: Le Chatelier's Principle
In a way you can think about Le Chatelier's Principle as the homeostasis of a reaction. When something in the reaction changes, the reaction responds accordingly. If more reactants were to be added, the reaction would respond by forming more products. If more products were added, then more reactants...
- Sun Jan 12, 2020 8:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Inert Gases
- Replies: 4
- Views: 181
Inert Gases
Does anyone know other examples of inert gases besides helium or argon, or are they all just noble gases?
- Sun Dec 08, 2019 12:44 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Memorizing Ligands
- Replies: 3
- Views: 249
Re: Memorizing Ligands
Another one is diethylenetriamine (dien), which is NH2CH2CH2NHCH2CH2NH2.
- Sun Dec 08, 2019 12:41 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand Polydentate
- Replies: 1
- Views: 255
Re: Ligand Polydentate
I think an easy way to tell is to see if there are multiple atoms with lone pairs attached. Like with ethylenediamine, its nitrogen atoms have a set of lone pairs, allowing it to be a bonding site.
- Sun Dec 08, 2019 12:37 am
- Forum: Naming
- Topic: bis- tris- tetrakis-
- Replies: 8
- Views: 633
Re: bis- tris- tetrakis-
Also as a quick tip, I believe you write the polydentate in parenthesis when using the prefixes.
- Sun Dec 08, 2019 12:35 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR and polarity
- Replies: 8
- Views: 666
Re: VSEPR and polarity
Tetrahedral I believe is one of these examples. It tends to be polar but in cases such as CH4, the structure become neutral. This is because all of the surrounding atoms are the same and their dipoles "cancel out."
- Sun Dec 08, 2019 12:29 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final tips
- Replies: 19
- Views: 1084
Re: Final tips
Working with others is always beneficial, since one person does not have the same information as another person, and overall helps with encouragement and support.
- Sun Dec 08, 2019 12:27 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ph and poH of weak acids
- Replies: 8
- Views: 437
Re: Ph and poH of weak acids
I think the emphasis may be placed more on strong acids, but I would prepare for that anyway.
- Sat Dec 07, 2019 9:46 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: Polarity/Dipoles
- Replies: 1
- Views: 167
Polarity/Dipoles
What does it mean when dipoles "cancel out?"
- Sat Dec 07, 2019 9:44 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: resonance in relation to pH
- Replies: 2
- Views: 236
resonance in relation to pH
How does resonance affect the pH of an acid/base?
- Sat Dec 07, 2019 9:42 pm
- Forum: Biological Examples
- Topic: Coordination Compounds
- Replies: 2
- Views: 111
Coordination Compounds
Which coordination compounds do we for sure need to know for the final?
- Sat Dec 07, 2019 4:17 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma Vs Pi
- Replies: 12
- Views: 823
Re: Sigma Vs Pi
Sigma bonds consist of two orbitals, one electron overlap from end to end, and can rotate. Pi bonds also have two orbitals with one electron overlap, but its side by side, and they cannot rotate.
- Sat Dec 07, 2019 4:08 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Compounds
- Replies: 2
- Views: 313
Re: Amphoteric Compounds
An amphoteric compound is one that shows both acidic and basic qualities. Like water, which is amphoteric, can react with acid to make a basic reaction, and with a base to make a more acidic counterpart.
- Sat Dec 07, 2019 4:04 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand polydentate
- Replies: 4
- Views: 419
Re: Ligand polydentate
I'm not entirely sure, but I think it depends on the lone pairs within a molecule. Like water is a monodentate because it can only bond through oxygen which has 2 sets of lone pairs. With en (ethylenediamine) since it has multiple nitrogens with lone pairs, it is able to bond through multiple site, ...
- Sat Dec 07, 2019 3:59 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: hydrogen bonding
- Replies: 3
- Views: 323
Re: hydrogen bonding
It's that, but when it's bonded to Fluorine, Oxygen, Sulfur, and nitrogen.
- Sat Dec 07, 2019 3:55 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Easier way to calculate/remember?
- Replies: 7
- Views: 393
Re: Easier way to calculate/remember?
For the oxidation numbers I just recommend keeping an eye out for negatively charged ligands.
- Sat Dec 07, 2019 3:50 pm
- Forum: Significant Figures
- Topic: Significant Figures during the Final.
- Replies: 1
- Views: 158
Significant Figures during the Final.
What do you do when your calculator cuts off a decimal before I get the required amount of significant figures? It's happened when my calculator decides to display the cut off decimal instead of the answer in scientific notation.
- Thu Dec 05, 2019 12:17 am
- Forum: DeBroglie Equation
- Topic: Quantum Help
- Replies: 5
- Views: 534
Quantum Help
I'm having trouble with quantum, since a lot of the problems require you to relate multiple equations with each other step by step. Does anyone have any tips on how to start, keeping your mind focused, and finding relationships between each equation?
- Thu Dec 05, 2019 12:12 am
- Forum: Naming
- Topic: Coordination Compound Charges
- Replies: 3
- Views: 213
Re: Coordination Compound Charges
For these sets of problems, yes we want their overall charge to be neutral. Just remember that the coordination compound/ligands must have a charge opposite to the "outside" ion.
- Thu Dec 05, 2019 12:08 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand Names
- Replies: 2
- Views: 150
Re: Ligand Names
If Lavelle posted that table himself, then I doubt that he would add some extra ones to the final. If you do happen to see one in the problems that occurs often but is not listed in the table, then it would be a good idea to write it down.
- Thu Dec 05, 2019 12:02 am
- Forum: Student Social/Study Group
- Topic: Finals Preparation
- Replies: 7
- Views: 618
Re: Finals Preparation
For breakfast, do what works the best for you and don't make any huge changes the day off. Like if you normally do not drink coffee, don't try taking a large coffee the morning of. Fruit is always a good idea, and eat enough so that you don't get hungry during the exam.
- Sun Dec 01, 2019 10:12 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Final
- Replies: 3
- Views: 456
Re: Final
I feel like since quantum overlaps a lot anything should be fine. For sure look over equations and key constants.
- Sun Dec 01, 2019 9:43 pm
- Forum: Bronsted Acids & Bases
- Topic: Final
- Replies: 13
- Views: 867
Re: Final
I say that for sure quantum and molecular shape/structure since we spent a lot of time emphasizing those.
- Sun Dec 01, 2019 9:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 5
- Views: 356
Re: Polydentate
A ligand is a polydentate when there are multiple molecules to that one ligand (like NH2CH2CH2NH which is a bidentate).
- Sun Dec 01, 2019 9:35 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 3
- Views: 267
Re: Final
Definitely look over quantum, since it was a large emphasis during the first half of the quarter.
- Sun Dec 01, 2019 9:28 pm
- Forum: Student Social/Study Group
- Topic: Final Studying
- Replies: 8
- Views: 385
Re: Final Studying
I would say look over any review sheets that were already given to us to refresh our memories on everything that we went over in the beginning. Also forming study groups with people helps a lot since everyone gets to help each other out. Also, if there are still some concepts that still don't make s...
- Sun Dec 01, 2019 9:10 pm
- Forum: Naming
- Topic: Neutral Ligands
- Replies: 2
- Views: 257
Re: Neutral Ligands
Neutral ligands include H2O (aqua), NH3 (ammine), NO (nitrosyl), CO (carbonyl), NH2CH2CH2NH (ethylenediamine), NH2CH2CH2NHCH2CH2NH2 (diethyltriamine).
- Sun Dec 01, 2019 9:01 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Final Study Methods
- Replies: 11
- Views: 683
Re: Final Study Methods
Another idea would be to redo the midterm questions. Since we got the test packet back, it wouldn't hurt to look over which problems we missed and get extra practice for what we went over at the beginning of the quarter.
- Mon Nov 25, 2019 12:00 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: NH3
- Replies: 4
- Views: 346
Re: NH3
A neutral atom? If you determine its formal charge, you'd use the equation (5-(2+6/2), which would equal 0. I'm guessing you're meaning non-polar or polar, and I believe that it is polar, since it's a tetrahedral molecule that doesn't have the same 4 atoms bound to its electron-dense regions. The m...
- Sun Nov 24, 2019 11:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR formula
- Replies: 5
- Views: 336
Re: VSEPR formula
There isn't a way to calculate bond angles (or at least in this course) because the exact angles are found experimentally. I think you will be fine if you just memorize the general bond angles given for each shape.
- Sun Nov 24, 2019 11:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape of carbon Dioxide
- Replies: 10
- Views: 641
Re: Molecular shape of carbon Dioxide
It's linear. There are no lone pairs on the central atom and it has 2 areas of electron density (VSEPR formula: AX2).
- Sun Nov 24, 2019 11:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic and Covalent character
- Replies: 4
- Views: 488
Re: Ionic and Covalent character
You could also ask Lavelle since he is making our final to double check.
- Sun Nov 24, 2019 11:44 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw shape
- Replies: 5
- Views: 266
Re: Seesaw shape
Seesaw occurs when a molecule has 5 areas of electron density and 1 lone pair (VSEPR formula: AX4E1).
- Sun Nov 24, 2019 11:41 pm
- Forum: Hybridization
- Topic: unused orbitals
- Replies: 4
- Views: 191
Re: unused orbitals
You leave it as a regular p orbital since it technically wasn't hybridized.
- Sun Nov 24, 2019 11:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: t shape and see saw
- Replies: 6
- Views: 455
Re: t shape and see saw
A molecular shape is a seesaw when the molecule has 5 areas of electron density and 1 lone pair. Tetrahederals have 4 areas of electron density and no lone pairs, but t shapes either have 5 areas of electron density and 2 lone pairs, or 6 areas of electron density and 3 lone pairs. (Basically t shap...
- Sun Nov 03, 2019 7:08 pm
- Forum: Lewis Structures
- Topic: Central Atom
- Replies: 3
- Views: 200
Re: Central Atom
There are times when the central atom has a positive/negative charge but that's only when the molecule has a positive/negative charge.
- Sun Nov 03, 2019 7:05 pm
- Forum: *Shrodinger Equation
- Topic: Schrondiger's Equation
- Replies: 6
- Views: 441
Re: Schrondiger's Equation
The main idea behind the equation is to find the location of an electron and its probability finding it at a certain point.
- Sun Nov 03, 2019 6:55 pm
- Forum: Significant Figures
- Topic: Sig figs on midterm
- Replies: 5
- Views: 330
Re: Sig figs on midterm
I would recommend paying attention to the sig figs in a problem to avoid losing points on the midterm.
- Sun Nov 03, 2019 6:53 pm
- Forum: Resonance Structures
- Topic: Resonance structures
- Replies: 15
- Views: 846
Re: Resonance structures
Resonance structure are basically like the synonyms of chemistry; it's when there are multiple ways to draw a lewis structure for a molecule.
- Sun Nov 03, 2019 6:50 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 5
- Views: 230
Re: Drawing Lewis Structures
When you draw a lewis structure you have to pay special attention to the valence electrons in each atom; they help determine if there are single/double/triple bonds. There is normally a center atom, and that is normally the atom that has the lowest ionization energy. For bonds (when the molecule is ...
- Tue Oct 22, 2019 11:01 pm
- Forum: Einstein Equation
- Topic: 1B.9
- Replies: 3
- Views: 154
1B.9
Can anyone explain why and how the equations c=lambda*frequency and E=hv are combined (E=c*h*lamdba^-1) to solve for this answer? I honestly don't understand how this works.
- Tue Oct 22, 2019 10:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Questions
- Replies: 2
- Views: 191
Re: Midterm Questions
I also talked to my PLF about midterms today, and she said this midterm could be more quantum heavy. It's a possibility but it doesn't help to study more on this subject.
- Tue Oct 22, 2019 10:37 pm
- Forum: DeBroglie Equation
- Topic: When to use the DeBroglie Equation
- Replies: 3
- Views: 129
Re: When to use the DeBroglie Equation
It works for problems that ask for the wavelength but list a momentum (m/s) instead of a frequency. As others have mentioned already, it is pretty similar to the equation, c=lamda*frequency; just be careful not to confuse the two.
- Tue Oct 22, 2019 10:26 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Online Modules
- Replies: 7
- Views: 239
Re: Online Modules
Just a thought, but if you think that there should be more modules, then you should ask Lavelle so he can post them for later terms.
- Wed Oct 09, 2019 6:37 pm
- Forum: Significant Figures
- Topic: Range of Sig Figs
- Replies: 8
- Views: 537
Re: Range of Sig Figs
Will the specific sig fig range be given before/in the test?
- Wed Oct 09, 2019 6:33 pm
- Forum: SI Units, Unit Conversions
- Topic: Test 1_Supplies [ENDORSED]
- Replies: 5
- Views: 227
Test 1_Supplies [ENDORSED]
Does anyone know if we have to provide our own periodic table for the test?
- Thu Oct 03, 2019 11:29 pm
- Forum: Significant Figures
- Topic: How would sig figs be used in a problem?
- Replies: 7
- Views: 210
Re: How would sig figs be used in a problem?
In a problem, sig figs would probably just be mentioned for rounding, like in keeping the final answer a certain number of sig figs.
- Thu Oct 03, 2019 11:25 pm
- Forum: Balancing Chemical Reactions
- Topic: Writing out equations
- Replies: 9
- Views: 568
Re: Writing out equations
I think some of the molecular formulas are given to us, such as the "less common ones", whereas compounds like carbon dioxide which are "more common" will not.
- Thu Oct 03, 2019 11:21 pm
- Forum: Empirical & Molecular Formulas
- Topic: 100 gram Method?
- Replies: 9
- Views: 1173
Re: 100 gram Method?
The 100 gram method is especially useful for when the problems don't give a specific mass for a molecule, but it gives the mass compositions. Just be careful when there is a specific mass given for a molecule; the 100 gram method probably won't work.