Search found 119 matches
- Fri Mar 12, 2021 7:34 pm
- Forum: Zero Order Reactions
- Topic: Overall reaction order
- Replies: 22
- Views: 1213
Re: Overall reaction order
As others said, it is possible but not very likely!
- Fri Mar 12, 2021 7:33 pm
- Forum: Zero Order Reactions
- Topic: When to use each order
- Replies: 19
- Views: 1203
Re: When to use each order
You can sum up the exponents from the rate law or look at the graphs!
- Fri Mar 12, 2021 7:32 pm
- Forum: *Enzyme Kinetics
- Topic: Absorption
- Replies: 3
- Views: 348
Re: Absorption
I think it was in Wednesday's lecture!
- Fri Mar 12, 2021 7:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Sapling Question week 9/10
- Replies: 5
- Views: 3403
Re: Sapling Question week 9/10
I was confused too, so thank you!!
- Fri Mar 12, 2021 7:29 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Gibbs Energy
- Replies: 20
- Views: 1181
Re: Gibbs Energy
Gibbs free energy tells us if the reaction is spontaneous or not.
- Sun Mar 07, 2021 8:31 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: pseudo rate law
- Replies: 13
- Views: 1131
Re: pseudo rate law
The pseudo rate law assumes that the other reactants are in large excess and so you can measure the isolated reactant. It is like what Lavelle said about taking 3 dollars from someone who has one million dollars!
- Sun Mar 07, 2021 8:30 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: K
- Replies: 10
- Views: 705
Re: K
Determining K depends on the question. You can use the graphs or can calculate K based on what variables are given in the problem.
- Sun Mar 07, 2021 8:28 pm
- Forum: General Rate Laws
- Topic: Multiple Reactants
- Replies: 7
- Views: 407
Re: Multiple Reactants
Hi! We covered multiple reactants in Friday's lecture (3/5).
- Sun Mar 07, 2021 8:27 pm
- Forum: General Rate Laws
- Topic: plotting a graph in experiements?
- Replies: 5
- Views: 342
Re: plotting a graph in experiements?
I do not think there is. I think it is experimentally determined.
- Sun Mar 07, 2021 8:26 pm
- Forum: General Rate Laws
- Topic: Units
- Replies: 10
- Views: 491
Re: Units
The units should work out when you do the equations. But generally, zero order is M/s, 1st order is 1/s and 2nd order is 1/M*s.
- Sun Feb 28, 2021 5:14 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Which Nesnst Equation
- Replies: 25
- Views: 1281
Re: Which Nesnst Equation
The log equation is only used when the reaction is at 25C or 298K. The ln equation is used any other time.
- Sun Feb 28, 2021 5:13 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E naught = 0
- Replies: 13
- Views: 2050
Re: E naught = 0
E naught is zero because the concentrations are equal in the cell.
- Sun Feb 28, 2021 5:12 pm
- Forum: Balancing Redox Reactions
- Topic: adding water in the reaction
- Replies: 13
- Views: 749
Re: adding water in the reaction
Water is used if the oxygens are not balanced.
- Sun Feb 28, 2021 5:11 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation vs Reduction
- Replies: 30
- Views: 1487
Re: Oxidation vs Reduction
I like using OIL RIG but I think any acronym is helpful to remember it!
- Sun Feb 28, 2021 5:10 pm
- Forum: Balancing Redox Reactions
- Topic: Understanding Oxidation Agents
- Replies: 13
- Views: 716
Re: Understanding Oxidation Agents
Hi! You shouldn't need knowledge from 14a (though we touched on it briefly) but just remember that strong oxidizing agents are easily reduced.
- Sun Feb 28, 2021 5:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding Pt(s) to the cell diagram
- Replies: 13
- Views: 592
Re: Adding Pt(s) to the cell diagram
In aqueous solutions, you need a conductor so if no metal is listed you need to add P(t).
- Sun Feb 28, 2021 5:07 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode/Cathode
- Replies: 45
- Views: 1762
Re: Anode/Cathode
Yes the anode is on the left and the cathode is on the right.
- Sun Feb 28, 2021 5:06 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: What is Potential?
- Replies: 14
- Views: 672
Re: What is Potential?
Standard reduction potential is the power of gaining electrons/being reduced.
- Wed Feb 17, 2021 3:39 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Problem 4F.13 Concept Question
- Replies: 1
- Views: 170
Problem 4F.13 Concept Question
Hi! When we want to freeze liquid water at 0 degrees Celsius, we use deltaS = Hfusion/T. Why do we make Hfusion a negative value? It is listed as 6.01 KJ/mol, but in calculations, we make it negative (example question 4F.13). Why do we do this? Thanks!
- Tue Feb 16, 2021 11:50 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Textbook 4J.5
- Replies: 2
- Views: 279
Textbook 4J.5
Hello! The problem is, "Write a balanced chemical equation for the formation reaction of (a) NH 3 (g ) ; (b) H 2 O (g ) ; (c) CO (g); (d) NO 2 (g ) . For each reaction, determine Δ H °, Δ S °, and Δ G ° from data in Appendix 2A.
How would you approach this problem? I am pretty lost, thanks.
How would you approach this problem? I am pretty lost, thanks.
- Mon Feb 15, 2021 4:22 pm
- Forum: Calculating Work of Expansion
- Topic: Irreversible vs reversible
- Replies: 5
- Views: 329
Irreversible vs reversible
How do you know if a reaction or system is reversible or irreversible? Thanks!
- Sun Feb 14, 2021 2:59 pm
- Forum: Phase Changes & Related Calculations
- Topic: Sapling Week 3/4 #9
- Replies: 5
- Views: 332
Re: Sapling Week 3/4 #9
Delta Ssurr is -delta H/ T and then Suniverse is the sum of the other two answers.
- Sun Feb 14, 2021 2:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: Week 5/6 Sapling Question 7
- Replies: 5
- Views: 339
Re: Week 5/6 Sapling Question 7
Everything is right except it is final - initial. Then your calculations should work!
- Sun Feb 14, 2021 1:12 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Including n
- Replies: 11
- Views: 580
Including n
Hello! Sometimes I have noticed we omit n in calculations for thermochemistry and sometimes we have to use PV=nRT to solve for n before doing further calculations (for example, #4 vs. #5 on sapling week 6 hw). When can we ignore n? Thanks!
- Wed Feb 10, 2021 8:02 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Textbook Problem 4D.15
- Replies: 3
- Views: 288
Textbook Problem 4D.15
Hi! The problem is: "Determine the reaction enthalpy for the hydrogenation of ethyne to ethane, C2H2+2H2---->C2H6 from the following data: Delta h sub c (C2H2,g)=-1300kJ.mol. Delta h sub c(C2H6,g)=-1560kJ.mol, and delta H sub c(H2,g)=-286 KJ.mol" I'm sorry but I do not even know where to b...
- Mon Feb 08, 2021 7:47 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbok Problem 4B.3
- Replies: 3
- Views: 217
Re: Textbok Problem 4B.3
Sophia Wendin 3L wrote:I think the textbook answer of 90 x 10^2 is an error. The solution manual says the answer is 4.9 x 10^2 which is what I got when I solved for w = deltaU - q.
Thank you I was so confused!!
- Mon Feb 08, 2021 7:46 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbook Problem 4A.3
- Replies: 2
- Views: 123
Re: Textbook Problem 4A.3
Thank you!
- Mon Feb 08, 2021 3:29 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbok Problem 4B.3
- Replies: 3
- Views: 217
Textbok Problem 4B.3
Hello! The problem is, "The internal energy of a system increased by 982 J when it was supplied with 492 J of energy as heat. (a) Was work done by or on the system? (b) How much work was done?"
I understand that work is done on the system, but how does work = 90 x 10^2 J? Thanks!
I understand that work is done on the system, but how does work = 90 x 10^2 J? Thanks!
- Mon Feb 08, 2021 1:06 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbook Problem 4A.3
- Replies: 2
- Views: 123
Textbook Problem 4A.3
Hello! This problem states, "Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump is 3.0 cm and the pump is depressed 20. cm with a pressure of 2.00 atm. (a) How much work is done in the compression? (b) Is the work positive or negative with respect to th...
- Wed Feb 03, 2021 4:51 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Units
- Replies: 11
- Views: 439
Re: Units
Textbook use J/gC, but I guess it could be Kelvin instead depending on what is given. I would just focus on making sure your units are all the same/cancel properly.
- Wed Feb 03, 2021 4:50 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Using Bond enthalpies
- Replies: 9
- Views: 470
Re: Using Bond enthalpies
I think on a test Lavelle would give us the value. For homework, you can find accurate values in the appendix/back of book.
- Wed Feb 03, 2021 4:48 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Stable Form in Enthalpies of Formation
- Replies: 11
- Views: 540
Re: Stable Form in Enthalpies of Formation
I think we just have to memorize a few of them (diatomic gases are in their most stable forms, solid carbon is in its most stable form, etc.) If it is outside of examples given in homework and class, I would expect Lavelle to clarify.
- Wed Feb 03, 2021 4:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond enthalpy method
- Replies: 10
- Views: 411
Re: Bond enthalpy method
Bond enthalpies are the least accurate because they are averages. Standard enthalpies of formation are most accurate, then Hess's Law.
- Wed Feb 03, 2021 4:44 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorize bond enthalpies / standard enthalpies of formation?
- Replies: 39
- Views: 1534
Re: Memorize bond enthalpies / standard enthalpies of formation?
No! Lavelle basically never asks us to memorize constants. It will be given in the problem.
- Wed Feb 03, 2021 4:43 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess Law
- Replies: 7
- Views: 504
Re: Hess Law
I think doing practice problems is the easiest way to learn. Basically, it is just flipping and multiplying the reactions to cancel out all reactants/products that you do not want. Just be sure to change the sign on delta H or multiply it! Whatever you do to the reaction, you have to do to delta H. ...
- Thu Jan 28, 2021 5:43 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Problem 6C.7 Help
- Replies: 3
- Views: 124
Problem 6C.7 Help
I can't find +NH3OH- or (CH3)2NH2+ on the table. Am I missing something or are we supposed to determine its strength without pKa?
- Thu Jan 28, 2021 1:04 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Textbook 5I.13
- Replies: 1
- Views: 76
Textbook 5I.13
For part b (using F2), I keep getting [F2]=2.38x10^-34 and [F]=0.0015. This does not match the solution manual. Does anyone else have this problem/know what I did wrong? Thanks!
- Wed Jan 27, 2021 12:56 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Textbook 6D.5
- Replies: 1
- Views: 89
Textbook 6D.5
This problem asks to calculate the pH, pOH, and percentage protonation of solute in each of the following aqueous solutions: a) 0.057M NH3 (aq). I am confused on how to solve this problem. The textbook gives me the and pKb, but how do I use these to get to pH? Thanks!
- Tue Jan 26, 2021 2:44 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Quadratic Equation Question
- Replies: 3
- Views: 106
Re: Quadratic Equation Question
Thank you guys!
- Tue Jan 26, 2021 12:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Quadratic Equation Question
- Replies: 3
- Views: 106
Quadratic Equation Question
I was doing #25 from Problem 5I and when solving for x, neither one of the values was negative (one was 0.042 and the other was 0.019). How do you know which one to use if they are both positive? Thanks!
Also side note, for this problem I know you use 0.019 but I do not know why. Thanks!
Also side note, for this problem I know you use 0.019 but I do not know why. Thanks!
- Mon Jan 25, 2021 4:48 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Problem 5I 25 ICE Table Help
- Replies: 3
- Views: 187
Re: Problem 5I 25 ICE Table Help
The question is: "A reaction mixture is prepared by mixing 0.100 mol SO2, 0.200 mol NO2, 0.100 mol NO, and 0.150 mol SO3 in a 5.00-L reaction vessel. The reaction SO2(g) NO2(g) --> NO(g) SO3(g) is allowed to reach equilibrium at 460 C, when Kc 85.0. What is the equilibrium concentration of each...
- Mon Jan 25, 2021 4:47 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Problem 5I 25 ICE Table Help
- Replies: 3
- Views: 187
Problem 5I 25 ICE Table Help
In this problem, the initial concentrations are given for both of the reactants (SO2 and NO2) and one of the products (SO3 but NOT NO). How would you set up an ICE table for this reaction? For the reactants, would it still be -x, -x, and for the products +x, and +x? Or would this change because the ...
- Mon Jan 25, 2021 3:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q Calculations
- Replies: 21
- Views: 1155
Q Calculations
When solving for Q, if the concentrations are given in mmol/L, do you have to change them to mol/l? Thanks!
- Mon Jan 25, 2021 12:20 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Total Pressure
- Replies: 26
- Views: 2176
Re: Total Pressure
Total pressure is just the sum of all the partial pressures!
- Mon Jan 25, 2021 12:19 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Determining pH
- Replies: 18
- Views: 911
Re: Determining pH
Use -log[H+] to get the pH and -log[OH-] for the pOH. You can also subtract from 14 to find one or the other!
- Mon Jan 25, 2021 12:18 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Ice Tables
- Replies: 28
- Views: 1257
Re: Ice Tables
You use -x when the reactants are turning into products and +x when the products are forming.
- Mon Jan 25, 2021 12:17 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Qudratic Formula
- Replies: 19
- Views: 1123
Re: Qudratic Formula
It could just be an algebra mistake. A lot of times it can be hard to type everything into the calculator correctly (I have made simple mistakes from this before!)
- Mon Jan 25, 2021 12:16 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 21
- Views: 1038
Re: Le Chatelier's Principle
I think just how pressure, volume, temperature, and concentration changes the equilibrium of a reaction.
- Fri Jan 22, 2021 5:41 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Problem 5G-9
- Replies: 3
- Views: 120
Problem 5G-9
In this textbook problem, it says although (PO2)3/(PO3)2 is the same, (PO2)/(PO3) will be different. Why is this the case? I thought that they would both be the same. Thanks!
- Fri Jan 22, 2021 5:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: H2O and K
- Replies: 11
- Views: 497
H2O and K
In textbook problem 5G-3, the H2O concentration is included in K. Is this because H2O is in its gas state? Thanks!
- Tue Jan 19, 2021 5:07 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE table values
- Replies: 20
- Views: 966
Re: ICE table values
Lavelle seems to only use mol/L. I am not sure if other units are acceptable but in this class but it seems like we only need to know mol/L.
- Tue Jan 19, 2021 5:05 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka vs. Kb
- Replies: 30
- Views: 5500
Re: Ka vs. Kb
They are both constants. Ka is for acids and Kb is for bases.
- Tue Jan 19, 2021 5:04 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Table
- Replies: 3
- Views: 121
ICE Table
How do we know when we can approximate x when using an ICE table? Thanks!
- Tue Jan 19, 2021 5:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa and Ka
- Replies: 27
- Views: 1111
pKa and Ka
Is pKa just the log of Ka? Or are they related in a different way? Thanks!
- Tue Jan 19, 2021 5:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Water in Reactions
- Replies: 7
- Views: 333
Water in Reactions
When do we include water in K calculations? Lavelle said something about when it is not a solvent but I am still confused. Thanks!
- Thu Jan 07, 2021 6:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: What is an activity?
- Replies: 9
- Views: 475
Re: What is an activity?
This also confused me! I think it is just referring to K though.
- Thu Jan 07, 2021 6:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: How do you know when to use Kc vs Kp?
- Replies: 9
- Views: 644
Re: How do you know when to use Kc vs Kp?
I think the question would specify if it wanted a concentration (Kc) or partial pressure (Kp). If only gases are involved, I think it would most likely be Kp though. Hope this helps!
- Thu Jan 07, 2021 6:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Including H2O
- Replies: 7
- Views: 375
Re: Including H2O
Liquids and solids are never included in K calculations because they don't have a concentration.
- Thu Jan 07, 2021 6:16 pm
- Forum: Ideal Gases
- Topic: K and PV=nRT
- Replies: 9
- Views: 965
Re: K and PV=nRT
It depends on what the problem asks for! Use PV=nRT when you are converting from partial pressure to concentration or the opposite. For problems that ask for Kp, you'd plug in the pressure of each reactant/product instead of their concentrations. Hope this helped!
- Thu Jan 07, 2021 6:13 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: names for reaction quotient Q
- Replies: 19
- Views: 638
Re: names for reaction quotient Q
Qp and Qc are all Q just with different units (pressures vs. concentrations).
- Thu Jan 07, 2021 6:11 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs. Q
- Replies: 53
- Views: 2565
K vs. Q
Hi! Just to clarify, Q and K are both the ratio of products over reactants, the only difference is that Q is used when the reaction is not at equilibrium? Thanks!
- Sun Dec 13, 2020 2:07 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ka and pKa
- Replies: 5
- Views: 511
Re: Ka and pKa
Higher Ka values indicate lower pKa values and lower Ka values indicate higher pKa values. They are inversely related.
- Sun Dec 13, 2020 2:05 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pH and pKA
- Replies: 6
- Views: 420
Re: pH and pKA
As others said, if pH is less than pKa, then the environment is going to be more acidic. So, it is making an acidic environment more acidic.
- Sun Dec 13, 2020 2:03 pm
- Forum: Student Social/Study Group
- Topic: Final Exam
- Replies: 49
- Views: 3103
Re: Final Exam
Yes, I felt the same! I had no problems with time for the midterms but on this final, I was rushed.
- Fri Dec 11, 2020 12:19 am
- Forum: Hybridization
- Topic: Textbook 2F #7b Hybridization
- Replies: 1
- Views: 93
Textbook 2F #7b Hybridization
Hi! The textbook asked for the hybridization of AsF3. I was confused why this would have hybridization since the electron configuration for As already has 3 empty spots for electrons ([Ar]3d10 4s2 4p3)? Can someone explain why this still uses hybridization? Thanks!
- Wed Dec 09, 2020 8:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle Question
- Replies: 2
- Views: 239
Bond Angle Question
Hi! To determine bond angles, I use a VSPER Theory sheet that my TA gave us to study. But, in the textbook, I've noticed that sometimes the angle is different. An example is CH3-. I drew it and found that it was a trigonal pyramid and the formula was AX3E. So, the angle would be 109.5. But, the text...
- Wed Dec 09, 2020 8:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Textbook 2E #25
- Replies: 3
- Views: 193
Textbook 2E #25
Hi! The textbook question asked if SF4 was polar or nonpolar. I drew it and found that it was seesaw shape, so the dipoles do not cancel, so it is polar. But, the solutions manual says it is nonpolar. Am I missing something or is this a mistake?
- Sun Dec 06, 2020 3:30 pm
- Forum: Naming
- Topic: Order of Ligands/naming
- Replies: 28
- Views: 1361
Re: Order of Ligands/naming
The ligands are written in alphabetical order, but excluding the prefixes. Then, add the transition metal at the end. Hope this helps!
- Sun Dec 06, 2020 3:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 6
- Views: 383
Re: Final
I believe Friday is a review session. Also, I believe in an email he said the final will focus on the material that we spent the most time on (quantum). Hope this helps!
- Sun Dec 06, 2020 3:22 pm
- Forum: Lewis Acids & Bases
- Topic: lewis vs bronsted
- Replies: 8
- Views: 598
Re: lewis vs bronsted
A Lewis acid accepts electron pairs (ex. BF3) while a Bronsted acid donates a proton (ex. HCl). I think Lavelle said that Lewis definitions focus on the electrons while Bronsted definitions focus on the protons.
- Sun Dec 06, 2020 3:20 pm
- Forum: Bronsted Acids & Bases
- Topic: bronsted vs. lewis acid
- Replies: 10
- Views: 456
Re: bronsted vs. lewis acid
A Lewis acid accepts electron pairs (ex. BF3) while a Bronsted acid donates a proton (ex. HCl).
- Fri Dec 04, 2020 4:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Textbook Question 2E #25
- Replies: 2
- Views: 116
Textbook Question 2E #25
This question asked to draw the molecule and determine if it was polar or nonpolar. The molecule CCl4 was listed as polar, but I thought it would be nonpolar since the dipole moments cancelled out. What am I missing? Thanks!
- Sat Nov 28, 2020 4:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Axial vs Equatorial
- Replies: 4
- Views: 282
Re: Axial vs Equatorial
Axial atoms form a 180-degree angle. They are vertical from each other (like above or below each other). Equatorial atoms are along the same equatorial plane. Dr. Lavelle went over some diagrams that helped me understand this!
- Sat Nov 28, 2020 3:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sapling Weeks 7-8 #16
- Replies: 6
- Views: 331
Re: Sapling Weeks 7-8 #16
Delocalized pi bonds correlate to the structure having resonance with double or triple bonds!
- Sat Nov 28, 2020 3:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Delocalized Pi Bond
- Replies: 7
- Views: 262
Re: Delocalized Pi Bond
I think delocalized correlates to if the structure has resonance or not. If it has resonance, then the electrons would be delocalized because they don't have one singular place.
- Sat Nov 28, 2020 3:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape Names
- Replies: 50
- Views: 2720
Re: Shape Names
Bent and angular are the same thing!
- Sat Nov 28, 2020 3:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity and Shape
- Replies: 13
- Views: 727
Re: Polarity and Shape
I think just drawing them and seeing if the dipoles cancel out is the easiest!
- Fri Nov 20, 2020 11:43 am
- Forum: Octet Exceptions
- Topic: Octet Rule Exceptions
- Replies: 20
- Views: 1505
Re: Octet Rule Exceptions
P, S, and Cl, are elements that can have an expanded octet.
- Fri Nov 20, 2020 11:41 am
- Forum: Hybridization
- Topic: Energy level of sp3
- Replies: 2
- Views: 222
Re: Energy level of sp3
There is a crash course video that has good visuals and helped me understand. Hope this helps!
- Fri Nov 20, 2020 11:37 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: hydrogen bonding
- Replies: 7
- Views: 394
Re: hydrogen bonding
H bonding can only apply if there is a large difference in electronegativity, which is why it must be bonded to N O or F.
- Fri Nov 20, 2020 11:31 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: LDF forces
- Replies: 9
- Views: 511
Re: LDF forces
Everything has LDF regardless of the bond type!
- Fri Nov 20, 2020 11:30 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability vs Electronegativity
- Replies: 3
- Views: 368
Re: Polarizability vs Electronegativity
Yes, because polarizability is the ability of the electrons to be distorted and electronegativity is about gaining and losing electrons!
- Sun Nov 15, 2020 3:34 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Textbook Question
- Replies: 3
- Views: 159
Formal Charge Textbook Question
For question 2B #23, the textbook answer says the structure to the right is the more likely. But, the structures on the right are the ones that have formal charges, while the structures on the left all have 0 formal charges. What am I missing? Thanks!
- Sat Nov 14, 2020 6:16 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 22
- Views: 1016
Re: Midterm 2
I think the textbook problems are the most helpful!
- Fri Nov 13, 2020 11:15 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration Confused
- Replies: 3
- Views: 224
Re: Electron Configuration Confused
The way it fills matches up with the Aufbau diagram that I believe you are talking about, but when we write out electron configurations for this class, we would always go by increasing n levels. So, for example, even though 4s would fill before 3d, for a certain metal, lets say Ni, we would still w...
- Thu Nov 12, 2020 6:40 pm
- Forum: Lewis Structures
- Topic: Resonance Hybrid
- Replies: 5
- Views: 359
Re: Resonance Hybrid
The most stable structure (the one with the least amount of formal charges) is the structure that contributes the most.
- Thu Nov 12, 2020 6:38 pm
- Forum: Dipole Moments
- Topic: London Interactions
- Replies: 5
- Views: 326
Re: London Interactions
From what I understand, yes, London dispersion forces are always present regardless of bond type.
- Thu Nov 12, 2020 6:20 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration Confused
- Replies: 3
- Views: 224
Electron Configuration Confused
When I looked up the Aufbau Principle, it showed the diagram of the order that shells should be filled up (1s...5s, 4d). But, in the textbook answers, it lists 4d then 5s. What is the correct filling order for electron configurations? Thanks!
- Mon Nov 09, 2020 3:38 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Sapling 1D #23 Problem Quantum Numbers
- Replies: 2
- Views: 130
Re: Sapling 1D #23 Problem Quantum Numbers
Thank you so much!!
- Mon Nov 09, 2020 2:23 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Sapling 1D #23 Problem Quantum Numbers
- Replies: 2
- Views: 130
Sapling 1D #23 Problem Quantum Numbers
The question in the textbook asks: How many orbitals can have the following quantum numbers in an atom: (a) n=2, l=1 b) n=4, l=2, ml=-2 c) n=2 d) n=3, l=2, ml=+1 For part a, I understand that the electron configuration would be 2p, so there are 3 orbitals. But for part b and part d, I don't understa...
- Wed Nov 04, 2020 10:25 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Textbook question 1E 21
- Replies: 3
- Views: 223
Re: Textbook question 1E 21
Yes exactly! I like to draw diagrams, it helps me visualize where all the electrons are.
- Wed Nov 04, 2020 10:24 pm
- Forum: Administrative Questions and Class Announcements
- Topic: How to find my posts
- Replies: 163
- Views: 177639
Re: How to find my posts
You can go to "Quick links" and then click "Your posts"
- Wed Nov 04, 2020 10:22 pm
- Forum: Properties of Light
- Topic: How are you guys studying for the midterm?
- Replies: 19
- Views: 1137
Re: How are you guys studying for the midterm?
I thought the modules on his website were super helpful because there are concept questions too!
- Wed Nov 04, 2020 10:21 pm
- Forum: Octet Exceptions
- Topic: "Octets" beyond 8
- Replies: 6
- Views: 319
Re: "Octets" beyond 8
The expanded octect I think is more stable because atoms in those periods have d-orbitals which can have more electrons.
- Wed Nov 04, 2020 10:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: Textbook Problem 2A.1
- Replies: 4
- Views: 161
Re: Textbook Problem 2A.1
The d-orbitals have lower energy than the s and p orbitals!
- Sun Nov 01, 2020 8:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14B Winter 2021
- Replies: 7
- Views: 370
Re: Chem 14B Winter 2021
I've heard it was the same!
- Sun Nov 01, 2020 8:45 pm
- Forum: Student Social/Study Group
- Topic: Test Scored for Midterm 1
- Replies: 49
- Views: 2672
Re: Test Scored for Midterm 1
I think they are double-checking the test so hopefully we get our scores back soon!
- Sun Nov 01, 2020 8:44 pm
- Forum: Student Social/Study Group
- Topic: Halloween!!!
- Replies: 73
- Views: 4427
Re: Halloween!!!
I dressed up as Rachel Green from Friends and painted pumpkins!
- Sun Nov 01, 2020 8:43 pm
- Forum: Properties of Light
- Topic: Sapling #10
- Replies: 11
- Views: 610
Re: Sapling #10
Maybe try rounding your answer differently?
- Sun Nov 01, 2020 8:43 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Sapling #4
- Replies: 8
- Views: 525
Re: Sapling #4
You just need to divide the total energy by the work function from the step yu did before and then you should get the answer!