Search found 106 matches
- Sun Mar 15, 2020 12:22 am
- Forum: Second Order Reactions
- Topic: 1st order vs 2nd order graphs
- Replies: 2
- Views: 230
Re: 1st order vs 2nd order graphs
oh that makes sense, thanks
- Sat Mar 14, 2020 9:58 pm
- Forum: Second Order Reactions
- Topic: 1st order vs 2nd order graphs
- Replies: 2
- Views: 230
1st order vs 2nd order graphs
can someone explain why first order graphs have a slope thats pos but 2nd order graphs have a neg slope (without using eq).
- Sat Mar 14, 2020 9:57 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Endgame 15b
- Replies: 5
- Views: 415
Re: Endgame 15b
Oh i guess pseudo rate constant k' is just using the reactant concentration that the rate is dependent on. that would be [B].
- Sat Mar 14, 2020 9:55 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Endgame 15b
- Replies: 5
- Views: 415
Re: Endgame 15b
Ya I dont understand how to get it directly.
- Sat Mar 14, 2020 9:23 pm
- Forum: Administrative Questions and Class Announcements
- Topic: ENDGAME Review Session
- Replies: 71
- Views: 5688
Re: ENDGAME Review Session
I was just confused on 14f if anyone can explain it.
- Sat Mar 14, 2020 9:23 pm
- Forum: Administrative Questions and Class Announcements
- Topic: ENDGAME Review Session
- Replies: 71
- Views: 5688
Re: ENDGAME Review Session
This was very helpful, thank you!
- Sat Mar 14, 2020 9:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Printing for Final
- Replies: 9
- Views: 744
Re: Printing for Final
He said that we submit the test online, so i dont think we even need to scan or print anything anymore
- Sat Mar 14, 2020 9:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final time
- Replies: 5
- Views: 499
Re: Final time
Ya his email says it is. Just make sure you log on at 11:15(i think that is the time)!
- Sat Mar 14, 2020 9:18 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts on Final
- Replies: 7
- Views: 565
Re: Catalysts on Final
can someone explain how you know something is a catalyst? im confused on that.
- Sat Mar 14, 2020 9:17 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: 7E.3
- Replies: 2
- Views: 310
Re: 7E.3
Oh that makes sense, so rate law and rate constant are proportional to each other?
- Sat Mar 14, 2020 9:14 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Endgame 1a
- Replies: 5
- Views: 518
Re: Endgame 1a
yes, just remember that the lower concentration is always in the products.
- Sat Mar 14, 2020 9:10 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell Diagram
- Replies: 21
- Views: 1192
Re: Cell Diagram
I am pretty sure cathode is always on right and anode is always on left. that is how it is always shown for problems. but i guess you can make cathode on left if you make electrons flowing towards left.
- Sat Mar 14, 2020 9:08 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Relationship between work, cell potential, and delta G
- Replies: 6
- Views: 685
Re: Relationship between work, cell potential, and delta G
When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work. I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free e...
- Sat Mar 14, 2020 9:05 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cells
- Replies: 8
- Views: 738
Re: Concentration Cells
Basically, the electrons flow through the different concentrations, where it goes from a higher to a lower concentration. The lower concentration will always be for your product.
- Sat Mar 14, 2020 2:08 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test 2 on Standard Cell Potential
- Replies: 6
- Views: 454
Re: Test 2 on Standard Cell Potential
Ya, so since Ecell is more negative for the lithium equation, the anode is lithium equation.
- Sat Mar 14, 2020 1:44 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow and Fast Step
- Replies: 7
- Views: 544
Slow and Fast Step
just to clarify, the slow step determines the rate of the overall rxn by determining the reaction order?
- Sat Mar 14, 2020 1:42 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: intermediates
- Replies: 8
- Views: 592
Re: intermediates
Think about them as something necessary to get from the reactants you want to products you want. they come along in process, but arent part of initial reactants or final products.
- Sat Mar 14, 2020 1:39 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: 7C.11 c)
- Replies: 2
- Views: 212
Re: 7C.11 c)
if you think about the rate equation...
rate= k [A]
increasing the concentration will increase the rate of the rxn as they are proportional to each other, but that does not mean it will affect k, the rate constant. also k is a constant, so it does not change over course of rxn.
rate= k [A]
increasing the concentration will increase the rate of the rxn as they are proportional to each other, but that does not mean it will affect k, the rate constant. also k is a constant, so it does not change over course of rxn.
- Sat Mar 14, 2020 1:29 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: 7E.3
- Replies: 2
- Views: 310
7E.3
7E.3 The presence of a catalyst provides a reaction pathway in which the activation energy of a certain reaction is reduced from 125 kJ*mol−1 to 75 kJ*mol−1. (a) By what factor does the rate of the reaction increase at 298 K, all other factors being equal? (b) By what factor would the rate change if...
- Sat Mar 14, 2020 1:27 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: A- frequency factor
- Replies: 2
- Views: 291
A- frequency factor
can someone explain how the frequency factor comes into play with everything?
- Sat Mar 14, 2020 1:26 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: determining a catalyst
- Replies: 5
- Views: 375
determining a catalyst
I am confused on how to determine if something is a catalyst. If you are given a reaction or multiple steps for a reaction, how do you know what the catalyst is?
- Sat Mar 14, 2020 1:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 12
- Views: 833
Re: Final
I am confused: if we are getting a time limit for this, then how does he track that we only take 3-4 hours to take the test from when he posts the test on the website.
- Sat Mar 14, 2020 1:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final- general questions
- Replies: 12
- Views: 938
Re: Final- general questions
Do you know what time tomorrow he is going to send the test out?
- Sat Mar 14, 2020 1:16 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final- general questions
- Replies: 12
- Views: 938
Re: Final- general questions
Ya, I am not as afraid for my grade as just being prepared going into the test.
- Sat Mar 14, 2020 1:15 pm
- Forum: Zero Order Reactions
- Topic: Equation with dt
- Replies: 6
- Views: 544
Re: Equation with dt
Just to add on, I never used this equation or others like this in the homework problems, so I want to know its usefulness for the final
- Sat Mar 14, 2020 1:14 pm
- Forum: Zero Order Reactions
- Topic: Equation with dt
- Replies: 6
- Views: 544
Equation with dt
Im confused, do we ever actually use the equations with dt?
ex: d[A]/-[A]^2 = k dt
ex: d[A]/-[A]^2 = k dt
- Sat Mar 14, 2020 1:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final- general questions
- Replies: 12
- Views: 938
Final- general questions
I am getting a little anxious because I do not know general details about this final. What is the exact time limit? How are we going to be tested, is it all online and are we using zoom/video recording site while taking the test? How is the test formatted? I just feel like I do not know all the info...
- Wed Feb 19, 2020 9:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: about the Midterm...
- Replies: 8
- Views: 596
Re: about the Midterm...
I think my main issue was freaking out when I enter the test. Just remember to breathe and relax before starting each assessment so you can answer each question with a clear mind and right direction. Good luck everyone!
- Wed Feb 19, 2020 9:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student - Part II [ENDORSED]
- Replies: 298
- Views: 265793
Re: Advice from a Medical Student - Part II [ENDORSED]
Thank you, this was so interesting and uplifting.
- Wed Feb 19, 2020 9:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lavelle's Office Hours
- Replies: 5
- Views: 466
Re: Lavelle's Office Hours
Does anyone know what Lavelle's office hours are like? Is it going over general HW problems and information, or do we need to ask him questions and bring our own HW problems in?
- Wed Feb 19, 2020 9:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Material
- Replies: 16
- Views: 1064
Test 2 Material
Since Test 2 has been postponed to a week later, does that mean we will also be responsible for all the info we learn next week?
- Wed Feb 19, 2020 9:47 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q=n*delta H
- Replies: 5
- Views: 569
Re: q=n*delta H
Whether you use delta H or C*delta T depends on the information you are given. If you have delta H reaction, for example, then you will use that value. If you don’t have that information and instead just have the material and it’s specific heat, as well as the temperature change, you will use that ...
- Wed Feb 19, 2020 9:45 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Delta s = 0
- Replies: 8
- Views: 701
Re: Delta s = 0
that is true for reversible isothermal expansion. for an irreversible rxn, delta s is greater than 0 and delta s surroundings is =0.
- Wed Feb 19, 2020 9:38 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Second law of thermodynamics
- Replies: 6
- Views: 511
Re: Second law of thermodynamics
it is natural for entropy to increase abd be greater than 0 because the world naturally will always has disorder. Only in conditions that aren't related to the real world, that is when entropy is =0.
- Wed Feb 19, 2020 9:31 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode and Cathode
- Replies: 14
- Views: 1036
Re: Anode and Cathode
how do the terms anode and cathode relate to oxidation and reduction. He used the latter pair of terms to define anode and cathode, but can someone explain this further?
- Wed Feb 19, 2020 9:27 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3614097
Re: Post All Chemistry Jokes Here
What did the bartender say when oxygen, hydrogen, sulfur, sodium, and phosphorus walking into the bar? OH SNaP!
- Wed Feb 19, 2020 9:23 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3614097
Re: Post All Chemistry Jokes Here
Here is a joke:
- Wed Feb 19, 2020 9:19 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Delta G and delta Gr
- Replies: 3
- Views: 439
Re: Delta G and delta Gr
when do we know when to write delta G r (with r as the subscript)? I see both but never understand when to write what when calculating it.
- Wed Feb 19, 2020 9:17 pm
- Forum: Balancing Redox Reactions
- Topic: Understanding Half-Reactions
- Replies: 11
- Views: 715
Re: Understanding Half-Reactions
Can you explain how to tell which is being oxidized and which is being reduced in a redox rxn?
- Wed Feb 19, 2020 9:15 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Numbers
- Replies: 7
- Views: 460
Re: Oxidation Numbers
Maya Pakulski 1D wrote:What are oxidation numbers used for?
I am also partly confused with this. I understand we use the oxidation numbers for redox reactions, but can you explain how it in an example?
- Wed Feb 19, 2020 9:12 pm
- Forum: Balancing Redox Reactions
- Topic: What is being reduced/oxidized in this rxn?
- Replies: 4
- Views: 375
Re: What is being reduced/oxidized in this rxn?
I think there is an error also. Yours looks correct.
- Wed Feb 19, 2020 9:09 pm
- Forum: Balancing Redox Reactions
- Topic: Redox reactions
- Replies: 2
- Views: 193
Re: Redox reactions
You put the H+ for the acidic solution on the opposite side of the H20 (when applicable to add it).
- Tue Feb 11, 2020 8:59 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: thermodynamically stable
- Replies: 6
- Views: 447
Re: thermodynamically stable
i never saw this in our notes. will we be tested on this?
- Tue Feb 11, 2020 8:58 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: thermodynamically stable
- Replies: 6
- Views: 447
thermodynamically stable
what does it mean to b thermodynamically stable? how does this relate to gibbs free energy?
- Mon Feb 10, 2020 8:58 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: higher molar entropies
- Replies: 2
- Views: 233
higher molar entropies
why does a monoatomic gas have higher entropy than a diatomic gas?
- Mon Feb 10, 2020 4:01 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal
- Replies: 9
- Views: 540
Re: Isothermal
Not necessarily. Isothermal means that there is no temperature change (aka deltaT = 0) whereas reversibility has to do with entropy and if total entropy is 0 (aka in a reversible system) or if entropy of the surroundings is 0 (aka in an irreversible system). Can you explain further how entropy rela...
- Mon Feb 10, 2020 3:54 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible vs irreversible expansions
- Replies: 2
- Views: 157
Reversible vs irreversible expansions
What is the difference between reversible and irreversible expansions?
- Sun Feb 09, 2020 10:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: heat cap for liquid water instead of solid water
- Replies: 1
- Views: 83
heat cap for liquid water instead of solid water
Why do you use the specific heat capacity for liquid water instead of solid water in this problem?
4C.11 How much heat is needed to convert 80.0 g of ice at 0.0 8C into liquid water at 20.0 8C (see Tables 4A.2 and 4C.1)?
4C.11 How much heat is needed to convert 80.0 g of ice at 0.0 8C into liquid water at 20.0 8C (see Tables 4A.2 and 4C.1)?
- Sun Feb 09, 2020 8:42 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: HW 4c.3
- Replies: 2
- Views: 283
HW 4c.3
4C.3 Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) at constant pressure; (b) at constant vol- ume. Treat the gas as ideal.
How do you differentiate what to do for constant pressure vs constant vol?
How do you differentiate what to do for constant pressure vs constant vol?
- Sun Feb 09, 2020 1:01 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: HW Question
- Replies: 2
- Views: 99
Re: HW Question
Also, isn't it usually qsys = -qsurr
so how is this different from the problems using that equation.
so how is this different from the problems using that equation.
- Sun Feb 09, 2020 1:00 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: HW Question
- Replies: 2
- Views: 99
HW Question
Hi. Im confused why we would add the heat of kettle and heat of water together for this problem in (a). 4A.7 (a) Calculate the heat that must be supplied to a copper kettle of mass 400.0 g containing 300.0 g of water to raise its tem- perature from 20.0 8C to the boiling point of water, 100.0 8C. (b...
- Thu Jan 23, 2020 2:18 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acids and Bases pka and pkb
- Replies: 8
- Views: 335
Re: Acids and Bases pka and pkb
Mariah wrote:Abhi Vempati 2H wrote:Adding on to what @Hui Qiao Wu 1I mentioned, the lower the pka of an acid, the higher the pKb of its conjugate base. This is because of the equation pka + pKb = 14. Hope this helps!
14 is the same as p[sub]w right?
Yes, Pkw=14
- Wed Jan 22, 2020 3:56 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Acids and Bases pka and pkb
- Replies: 8
- Views: 335
Acids and Bases pka and pkb
Can someone explain the relation btwn pkA/pkB and how strong the acid/base is. If I have a higher pkB, does that mean I have a weaker base?
- Wed Jan 22, 2020 1:36 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5J.13
- Replies: 5
- Views: 489
5J.13
5J.13 A gaseous mixture consisting of 2.23 mmol N2 and 6.69 mmol H2 in a 500.-mL container was heated to 600. K and allowed to reach equilibrium. Will more ammonia be formed if that equilibrium mixture is then heated to 700. K? For N2(g) + 3H2(g) --> 2NH3(g), K=1.7 x 10^-3 at 600.K and K=7.8 x 10^-5...
- Tue Jan 21, 2020 6:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: partial pressure
- Replies: 5
- Views: 282
partial pressure
what are the general units for partial pressure? I have seen bar and atm, so do both work depending on what the problem gives you?
- Tue Jan 21, 2020 5:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G part c
- Replies: 3
- Views: 179
5G part c
5G.1 State whether the following statements are true or false. If false, explain why.
(c) If one starts with a higher pressure of reactant, the equilibrium constant will be larger.
Can someone explain C to me? I understand it is false but i want to know the best way to explain it.
(c) If one starts with a higher pressure of reactant, the equilibrium constant will be larger.
Can someone explain C to me? I understand it is false but i want to know the best way to explain it.
- Wed Jan 15, 2020 6:26 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: HW 5J.5 part C
- Replies: 3
- Views: 185
HW 5J.5 part C
5J.5 State whether reactants or products will be favored by an increase in the total pressure (resulting from compression) on each of the following equilibria. If there is no change, explain why that is so.
(c) 4NH3(g)+ 5O2(g) -> HNO(g) + 6H2O(g) How do I know the reactants are favored in this case...
- Sun Dec 08, 2019 3:40 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid Strength- Acetic vs Formic Acid
- Replies: 4
- Views: 534
Re: Acid Strength- Acetic vs Formic Acid
So it is involving electronegativity...Im guessing.
- Sun Dec 08, 2019 3:39 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid Strength- Acetic vs Formic Acid
- Replies: 4
- Views: 534
Re: Acid Strength- Acetic vs Formic Acid
Oh I think I got it. It's because of the CH3 in acetic acid is electron donating, and it contributes e- density towards the O-H bond making the bond stronger to break and H+ ion less wanting to go and attach to another compound.
- Sun Dec 08, 2019 3:36 am
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Rod vs spherical shaped molecules
- Replies: 10
- Views: 1712
Re: Rod vs spherical shaped molecules
I get it now. The rod shaped molecs have greater surface area bc of more pts of interaction btwn 2 polar molecs, which causes a stronger interaction btwn the 2 molecs. therefore, a higher BP would be needed to break up the 2 molecs.
- Sat Dec 07, 2019 10:05 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
- Replies: 115
- Views: 13084
Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Naren_Ramesh_4D wrote:On question 2b of the mini marshmallow, does the order of the ligand in the coordination complex matter?
I dont think so
order of ligands matters in writing the name- alphabetical order
not in writing formula
- Sat Dec 07, 2019 1:40 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: HW 6D.11 part e
- Replies: 1
- Views: 594
HW 6D.11 part e
6D.11 Decide whether an aqueous solution of each of the following salts has a pH equal to, greater than, or less than 7. If pH . 7 or pH , 7, write a chemical equation to justify your answer. (e) AlCl3;
I am confused how to write the equation for Al +3. Why does it combine with H20 first?
I am confused how to write the equation for Al +3. Why does it combine with H20 first?
- Fri Dec 06, 2019 6:04 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid Strength- Acetic vs Formic Acid
- Replies: 4
- Views: 534
Acid Strength- Acetic vs Formic Acid
Problem 6C.21b: Why is formic acid stronger than acetic acid? I'm confused with the electronegativity/polarity aspect of it.
- Fri Dec 06, 2019 5:13 pm
- Forum: Lewis Acids & Bases
- Topic: List of Strong Acids/Bases
- Replies: 5
- Views: 358
Re: List of Strong Acids/Bases
Also, if anyone knows the full list of strong and weak acids and bases we need to memorize.
- Fri Dec 06, 2019 5:12 pm
- Forum: Lewis Acids & Bases
- Topic: List of Strong Acids/Bases
- Replies: 5
- Views: 358
List of Strong Acids/Bases
Does anyone have a good list that simply puts what to look for when trying to decide whether one acid/base is stronger than another?
- Thu Dec 05, 2019 10:31 pm
- Forum: Amphoteric Compounds
- Topic: Transition Metals
- Replies: 1
- Views: 248
Transition Metals
How do i know if a transition metal is amphoteric? Do we need to know specific ones for the final?
- Wed Dec 04, 2019 9:50 pm
- Forum: Naming
- Topic: HW Problem 9C 3d
- Replies: 1
- Views: 187
HW Problem 9C 3d
We are asked to write the formula for sodiumbisoxalato(diaqua)ferrate(III)
I'm confused how we know which ligand to put first and which to put second in the formula for the compound.
Also, why is diaqua in parentheses?
I'm confused how we know which ligand to put first and which to put second in the formula for the compound.
Also, why is diaqua in parentheses?
- Wed Dec 04, 2019 9:22 pm
- Forum: Naming
- Topic: Homework Problem 9C 3a
- Replies: 2
- Views: 237
Homework Problem 9C 3a
So the problem asks to write the formula for potassium hexacyanidochromate(III) I understand how to get the formula from this coordination compound name but I want to clarify a few things. 1)the -3 charge for hexacyanidochromate is not written outside the brackets bc it cancels out with the +3 charg...
- Wed Dec 04, 2019 3:39 pm
- Forum: Hybridization
- Topic: Hybridization General Question
- Replies: 3
- Views: 315
Hybridization General Question
In Homework question 2.45, it asks to write the hybridization of each lone pair in the bonding in H2C =(double bond) CHCHO. The drawing in the answer key says the lone pairs of O have a hybridization of sp2 but the hybridization of O when its bonded is 2sp2 (difference is the 2 in front). What does ...
- Wed Dec 04, 2019 2:25 pm
- Forum: Hybridization
- Topic: Drawing Acrylonitrile
- Replies: 1
- Views: 141
Drawing Acrylonitrile
Problem 2F.13 asks to draw Acrylonitrile, which is CH2CHCN, and then state the bond angles. How do I know which element is the central atom and how to organize the surrounding molecules? The drawing affects what bond angles I put, so is there a way to ensure I draw it correctly with all compounds si...
- Thu Nov 21, 2019 5:02 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 Homework Problem
- Replies: 2
- Views: 278
Hydrogen Bonding Homework Problem
3F.5 Suggest, giving reasons, which substance in each of the fol- lowing pairs is likely to have the higher normal melting point (Lewis structures may help your arguments): (a) HCl or NaCl; (b) C2H5OC2H5 (diethyl ether) or C4H9OH (butanol); (c) CHI3 or CHF3; (d) C2H4 or CH3OH. In B, why can buthanol...
- Wed Nov 13, 2019 9:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test #2
- Replies: 22
- Views: 2940
Re: Test #2
Do you think it will also have some information from the midterm as well? Or only new untested topics?
- Tue Nov 12, 2019 1:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test #2
- Replies: 22
- Views: 2940
Re: Test #2
Maybe we should ask Dr. Lavelle on Wednesday during the lecture, the test is coming up and I want to start preparing for it.
- Tue Nov 12, 2019 1:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 7 Homework
- Replies: 7
- Views: 298
Re: Week 7 Homework
I feel like the homework is pretty flexible in which concepts you can do it on that are relatively recent- I'm thinking concepts like dipole moments, intermolecular and intramolecular forces, and whatever is around that is all ok.
- Tue Nov 12, 2019 1:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Grades
- Replies: 3
- Views: 222
Re: Midterm Grades
Hiba Alnajjar_4B wrote:Not sure when they'll be posted, but Dr. Lavelle announced that we would be getting them back during Wednesday lecture, so maybe after Wednesday?
Are we reviewing the questions on the midterm during the lecture or just getting them back?
- Tue Nov 12, 2019 1:35 pm
- Forum: Dipole Moments
- Topic: Temporary Dipoles
- Replies: 5
- Views: 304
Temporary Dipoles
Can someone explain what a temporary dipole is and how it occurs? How does it happen on a nonpolar molecule?
- Tue Nov 12, 2019 1:32 pm
- Forum: DeBroglie Equation
- Topic: When to Use
- Replies: 8
- Views: 514
When to Use
I know the De Brogile Equation is used in certain circumstances, what are those? How do you know based on the wording of the question that you need to use this equation for your answer?
- Tue Nov 12, 2019 1:30 pm
- Forum: Lewis Structures
- Topic: Exceptions
- Replies: 5
- Views: 193
Exceptions
What elements have exceptions to the octet rule other than the ones that are past the 3rd period and can have more than an octet? I know there are specific elements that also like specific types of bonds, what are those elements?
- Tue Nov 12, 2019 1:27 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Rod vs spherical shaped molecules
- Replies: 10
- Views: 1712
Rod vs spherical shaped molecules
Can someone explain the key differences between rod shaped and spherical shaped molecules?
- Tue Nov 12, 2019 1:22 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 in Biological Systems
- Replies: 2
- Views: 191
Hydrogen Bonding in Biological Systems
Can someone explain why hydrogen bonding is so common in biological systems? I'm confused
- Tue Nov 12, 2019 1:07 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Wavelength Plausibility
- Replies: 31
- Views: 2694
Re: Wavelength Plausibility
Technically, if the question asks if the wavelength is detectable, or more often it will ask if there are "detectable wavelike properties" that means that it wants to know whether the wavelength is greater than 10e-15 or not. That makes a lot of sense! A good thing to look out for, thanks!
- Tue Nov 12, 2019 1:05 pm
- Forum: Administrative Questions and Class Announcements
- Topic: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
- Replies: 53
- Views: 5951
Re: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
All these worksheets were really helpful for reviewing for the midterm, thank you! Will any worksheets be posted to review for the upcoming Test 2? Thanks!
- Tue Nov 12, 2019 1:02 pm
- Forum: Student Social/Study Group
- Topic: Chemistry News
- Replies: 135
- Views: 167931
Re: Chemistry News
Wow! I just read some of these articles and they're so interesting! Thank you for sharing, keep them coming!
- Tue Nov 12, 2019 1:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Extra Credit?
- Replies: 6
- Views: 298
Topics on Test 2
Hey guys! Does anyone know the full range of topics covered on Test 2? I know it is coming up next week starting the 19th but I am unsure what exactly is on it.
- Tue Nov 12, 2019 12:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Extra Credit?
- Replies: 6
- Views: 298
Extra Credit?
I'm pretty sure Dr. Lavelle doesn't offer any extra credit or other opportunities to boost up your grade, but I just wanted to make sure on Chem Community. Thanks!
- Tue Nov 12, 2019 12:57 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Review Sessions?
- Replies: 6
- Views: 374
Test 2 Review Sessions?
Are there any review sessions and workshops available for the upcoming Test 2? Really nervous and wanted to get extra practice.
- Tue Nov 12, 2019 12:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Grades
- Replies: 3
- Views: 222
Midterm Grades
Does anyone know when our midterm grades will be posted onto myucla?
- Tue Nov 12, 2019 12:52 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Finding orbitals without given ml quantum number
- Replies: 2
- Views: 259
Finding orbitals without given ml quantum number
1D.23 How many orbitals can have the following quantum numbers in an atom: (a) n=2, l=1; (c) n=2?
I am confused with how to answer a and c because they don't give a mI value so there are multiple orbitals that can have those quantum numbers.
I am confused with how to answer a and c because they don't give a mI value so there are multiple orbitals that can have those quantum numbers.
- Tue Nov 12, 2019 12:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing full electron configuration
- Replies: 3
- Views: 380
Writing full electron configuration
If it says to write the full electron configuration in the ground state for an element, do you ever need to include the different subshells that show unpaired electrons? for example: for the full electron configuration of nitrogen, in the 2p-orbital do you write it out as [2px1 2py1 2pz1] or just [2...
- Tue Nov 12, 2019 12:38 pm
- Forum: Empirical & Molecular Formulas
- Topic: Answering a Question without amount of elements
- Replies: 1
- Views: 224
Answering a Question without amount of elements
When you don't get the amount in grams of each element in the question, what is the best way to find out those amounts? You would get the molar mass of the compound and the amounts of the other molecules in the equation. There was a question like this on the midterm.
- Tue Nov 12, 2019 12:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Studying
- Replies: 14
- Views: 904
Final Studying
Has anyone began reviewing for the final? If so, what are you doing to slowly prepare?
- Sun Oct 20, 2019 9:19 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Quick Question about orbitals
- Replies: 1
- Views: 185
Quick Question about orbitals
Quick question! Why does the # of orbitals increase by 2 per level? For example, why does S have 1 orbital and the next level, p, has 3 orbitals, d has 5 orbitals, etc? It increases by 2, why can't it increase by 1?
- Sun Oct 20, 2019 9:09 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Spin up and Spin down
- Replies: 2
- Views: 120
Spin up and Spin down
I am really confused with the spin up and spin down aspect we discussed in class. Can someone clear it up for me?
I also remember him saying that when both electrons are spin up, they interact differently than when they are spin down. Why?
I also remember him saying that when both electrons are spin up, they interact differently than when they are spin down. Why?
- Sun Oct 20, 2019 9:06 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Neon- electron configuration
- Replies: 3
- Views: 285
Neon- electron configuration
In class, Dr. Lavelle said that elements like Neon are not good at building bonds. Why is this so?
- Sun Oct 20, 2019 8:56 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Series
- Replies: 3
- Views: 178
Re: Series
The series is from the spectrum of hydrogen, as sequences of lines correspond to atomic transitions that each begin or end with the same atomic state in hydrogen. The Balmer series- all of the lines are in the visible region The Lyman series- ultraviolet region The Brackett series, Pfund series, Pas...
- Sun Oct 20, 2019 8:32 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Friday's lecture (4s and 3d)
- Replies: 3
- Views: 133
Re: Friday's lecture (4s and 3d)
The 4s sublevel is filled before the 3d sublevel because the 4s subshell is lower in energy, and it is farther from the nucleus than the 3d subshell.
- Sun Oct 13, 2019 7:23 pm
- Forum: Photoelectric Effect
- Topic: Electrons ejected based on wavelength
- Replies: 3
- Views: 174
Electrons ejected based on wavelength
I am confused why light sources with long wavelengths of light cannot eject electrons in the photoelectric experiment, but why light sources with short wavelengths can. Can someone clear this up for me?
- Sun Oct 13, 2019 7:19 pm
- Forum: Properties of Electrons
- Topic: Wavelike vs Particle-like Behavior
- Replies: 6
- Views: 282
Re: Wavelike vs Particle-like Behavior
I thought of this to mean that electrons behave both like particles and like waves. De Brogile explains that all material particles in motion have wave characteristics, but for microscopic bodies like electrons this observation is important. Electrons are under high speed, showing a wave-like appear...
- Sun Oct 13, 2019 6:57 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Textbook Problem- 1B.19
- Replies: 1
- Views: 86
Textbook Problem- 1B.19
Hi guys, I'm confused with this textbook problem. Can anyone describe the steps needed to complete the problem? 1B.19 Protons and neutrons have nearly the same mass. How different are their wavelengths? Calculate the wavelength of each particle when traveling at 2.75 x 10^5 mxs^-1 in a particle acce...
- Sun Oct 13, 2019 6:51 pm
- Forum: Properties of Light
- Topic: Quanta
- Replies: 4
- Views: 257
Re: Quanta
We use quantum mechanics to describe the behavior of very small objects that can accept energy only in discrete amounts. These discrete amounts are called quanta. It's easy for me to think about quanta as the smallest unit of any physical property- whether that is energy, matter, etc. It is like a p...