Search found 59 matches
- Wed Mar 13, 2019 5:19 pm
- Forum: First Order Reactions
- Topic: pseudo first order [ENDORSED]
- Replies: 5
- Views: 949
pseudo first order [ENDORSED]
In pseudo 1st order rate laws, why are the reactants in large excess left out?
- Wed Mar 13, 2019 5:11 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: catalyst vs intermediate
- Replies: 3
- Views: 646
catalyst vs intermediate
In catalyses, will the catalyst always be there to begin with and will the intermediate always be formed?
- Wed Mar 13, 2019 4:59 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: transition state
- Replies: 1
- Views: 230
transition state
What is a transition state/activated complex?
- Wed Mar 13, 2019 4:55 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: K and k
- Replies: 1
- Views: 231
K and k
Can someone please explain why K = k/k' for a multistep reaction?
- Wed Mar 13, 2019 3:27 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration cell product
- Replies: 1
- Views: 247
Concentration cell product
In a concentration cell, why do you have to make the lower concentration the product?
- Wed Mar 13, 2019 3:22 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration cell
- Replies: 1
- Views: 222
Concentration cell
Why is E0 always equal to 0 V in concentration cells?
- Wed Mar 13, 2019 3:15 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst equation
- Replies: 1
- Views: 415
Nernst equation
Can the equations E=E0-(RT/nF)lnQ and E=E0-(0.0592/n)lnQ be used interchangeably?
- Mon Mar 11, 2019 4:30 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Increasing reducing power
- Replies: 4
- Views: 1623
Increasing reducing power
How do you know what species have high reducing power?
- Mon Mar 11, 2019 4:29 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Increasing oxidizing power
- Replies: 2
- Views: 338
Increasing oxidizing power
How do you know what species have high oxidizing power?
- Mon Mar 11, 2019 3:46 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-equilibrium approach
- Replies: 1
- Views: 214
Pre-equilibrium approach
Can we only use the pre-equilibrium approach if we are given the observed rate for the overall reaction?
- Mon Mar 11, 2019 2:30 pm
- Forum: First Order Reactions
- Topic: Problem 7B.1 7th edition
- Replies: 1
- Views: 308
Problem 7B.1 7th edition
Why does the solution manual write the 1st order integrated rate law as ln[A]/[A]0 = -kt instead of ln[A] = -kt+[A]0? Do you get the same answer if you write it either way?
- Mon Mar 11, 2019 2:14 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Frequency factor A
- Replies: 7
- Views: 810
Frequency factor A
Can someone please explain what the frequency factor, A, is and what it tells us.
- Mon Mar 11, 2019 2:12 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Intermediates
- Replies: 8
- Views: 722
Intermediates
Why can there never be an intermediate in a rate law?
- Mon Mar 11, 2019 2:11 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre equilibrium approach
- Replies: 3
- Views: 451
Pre equilibrium approach
How do you know which elementary step will be approximately at equilibrium?
- Mon Mar 11, 2019 2:10 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: rate determining step
- Replies: 2
- Views: 334
rate determining step
How do you know which elementary step is the rate determining step?
- Mon Mar 11, 2019 2:08 pm
- Forum: First Order Reactions
- Topic: Integration
- Replies: 3
- Views: 504
Integration
Will we need to know how to integrate the differential rate law, or do we just need to know what the integrated rate law is?
- Mon Feb 25, 2019 2:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding Pt(s) to cell diagram
- Replies: 3
- Views: 364
Adding Pt(s) to cell diagram
How do you know when to add Pt(s) to a cell diagram?
- Mon Feb 25, 2019 2:00 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 2
- Views: 293
Cell Diagrams
In the example cell diagram we did in lecture, why are Cu(s) and Cu2+(aq) separated by a single line and Fe3+(aq) and Fe2+(aq) are separated by a comma?
Cu(s) | Cu2+(aq) and Fe3+(aq) , Fe2+(aq)
Cu(s) | Cu2+(aq) and Fe3+(aq) , Fe2+(aq)
- Mon Feb 25, 2019 1:34 pm
- Forum: Balancing Redox Reactions
- Topic: Adding H+, OH- and H20
- Replies: 4
- Views: 928
Adding H+, OH- and H20
Can someone please explain when to add H+, OH- or H20 when balancing redox reactions in acidic/basic solutions?
- Mon Feb 25, 2019 1:31 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing redox equations in acidic/basic solutions [ENDORSED]
- Replies: 3
- Views: 439
Balancing redox equations in acidic/basic solutions [ENDORSED]
Do we need to know how to balance redox equations in acidic/basic solutions for test 2?
- Tue Feb 12, 2019 11:37 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: deltaU=0
- Replies: 3
- Views: 454
deltaU=0
Why is the change in internal energy equal to zero when the process is isothermal?
- Sun Feb 10, 2019 5:47 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q and delta H
- Replies: 3
- Views: 437
q and delta H
When is it true that q=delta H?
- Sun Feb 10, 2019 5:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard reaction enthalpy vs standard enthalpy of formation
- Replies: 2
- Views: 365
Standard reaction enthalpy vs standard enthalpy of formation
Can someone please explain the difference between standard reaction enthalpy and standard enthalpy of formation?
- Sun Feb 10, 2019 2:21 pm
- Forum: Calculating Work of Expansion
- Topic: Integrals
- Replies: 3
- Views: 364
Integrals
For the midterm, do we need to know how to derive w=-PdeltaV using the integral?
- Sun Feb 10, 2019 2:19 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Homework Problem 4F.11
- Replies: 1
- Views: 240
Homework Problem 4F.11
In problem 4F.11, why does the solution use the equation deltaS= nRln(T2/T1) instead of nCpln(T2/T1)?
- Mon Jan 21, 2019 3:45 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH of weak acid and its salt
- Replies: 2
- Views: 328
pH of weak acid and its salt
In the example we did in lecture on Friday, why is the potassium not included in the equilibrium equation?
- Fri Jan 18, 2019 5:39 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6D.15
- Replies: 1
- Views: 144
6D.15
For homework problem 6D.15, how do you know what the Ka value is for AlCl3(aq)?
- Fri Jan 18, 2019 5:28 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: percentage protonation
- Replies: 2
- Views: 258
percentage protonation
Can someone please explain what the percentage protonation is? I understand how to find it, but I'm confused about what it tells you.
- Fri Jan 18, 2019 5:26 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Approximations
- Replies: 4
- Views: 417
Approximations
Why are we able to approximate when trying to find the pH of a weak acid/base?
- Wed Dec 05, 2018 5:08 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: group 1 and 2 anions
- Replies: 1
- Views: 144
group 1 and 2 anions
Why are cations from group 1 and 2 weak Lewis acids?
- Tue Dec 04, 2018 6:55 pm
- Forum: Bronsted Acids & Bases
- Topic: acidity
- Replies: 4
- Views: 593
acidity
Why are long, weaker A-H bonds more acidic than short, strong bonds?
- Tue Dec 04, 2018 6:48 pm
- Forum: Amphoteric Compounds
- Topic: amphoteric oxides
- Replies: 3
- Views: 382
amphoteric oxides
I know there is a diagonal band of amphoteric oxides, but is the only way to know which oxides are in this band by memorizing them? Or is the another way to know which are amphoteric?
- Tue Dec 04, 2018 6:32 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: strong or weak base
- Replies: 3
- Views: 625
strong or weak base
By just looking at a formula of a base, how would you know if it is a strong or weak base?
- Tue Dec 04, 2018 4:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: polydentate
- Replies: 2
- Views: 199
polydentate
How do you know if a ligand is polydenate?
- Tue Dec 04, 2018 4:39 pm
- Forum: Naming
- Topic: bis-,tris-,tetrakis-
- Replies: 2
- Views: 339
bis-,tris-,tetrakis-
What are some examples of when to use bis-,tris-,tetrakis-, etc?
- Tue Dec 04, 2018 4:24 pm
- Forum: Lewis Acids & Bases
- Topic: Homework Problem 6C.13
- Replies: 3
- Views: 342
Re: Homework Problem 6C.13
Okay thank you. I was confusing an acid being a protein donor but an electron pair acceptor.
- Mon Dec 03, 2018 5:46 pm
- Forum: Lewis Acids & Bases
- Topic: Homework Problem 6C.13
- Replies: 3
- Views: 342
Homework Problem 6C.13
In problem 6C.13 in the 7th edition book, part e asks to identify if H- is a Lewis acid or base. The answer key says it is a Lewis base, but it has a lone pair of electrons. Can someone please explain why it is a Lewis base?
- Tue Nov 27, 2018 9:01 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: dipole-dipole and dipole-induced dipole
- Replies: 2
- Views: 291
Re: dipole-dipole and dipole-induced dipole
Thank you! That was really helpful!
- Tue Nov 27, 2018 5:25 pm
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 7
- Views: 883
Polarity
When trying to figure out if a molecule is polar, I know it is helpful to draw the Lewis structure. If the Lewis structure has a lone pair, does that mean it is polar or not necessarily?
- Tue Nov 27, 2018 4:51 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: dipole-dipole and dipole-induced dipole
- Replies: 2
- Views: 291
dipole-dipole and dipole-induced dipole
Can someone please explain the difference between dipole-dipole and dipole-induced dipole interactions?
- Tue Nov 27, 2018 4:49 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: dipole-induced dipole
- Replies: 1
- Views: 251
dipole-induced dipole
What are some examples of molecules with dipole-induced dipole interaction?
- Tue Nov 27, 2018 4:43 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: 1
- Views: 152
hydrogen bonding
Why does hydrogen bonding only occur between H and N,O, or F?
- Tue Nov 27, 2018 4:33 pm
- Forum: Dipole Moments
- Topic: Intermolecular forces
- Replies: 4
- Views: 619
Re: Intermolecular forces
Thank you for that link! It really helps.
- Mon Nov 26, 2018 6:08 pm
- Forum: Hybridization
- Topic: Ethene example
- Replies: 2
- Views: 330
Ethene example
In the ethene example in lecture, why is there an unhybridized 2p orbital in addition to the hybridized 2sp2 orbital?
- Mon Nov 26, 2018 6:03 pm
- Forum: Dipole Moments
- Topic: Intermolecular forces
- Replies: 4
- Views: 619
Intermolecular forces
How can you tell if molecules have dipole-dipole or dipole-induced dipole forces?
- Mon Nov 26, 2018 5:57 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 1
- Views: 145
Hybridization
When does hybridization occur?
- Mon Nov 26, 2018 5:53 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi bonds
- Replies: 4
- Views: 668
Pi bonds
Why do pi bonds not allow bound atoms to rotate?
- Mon Nov 26, 2018 5:49 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Cis and Trans
- Replies: 10
- Views: 1004
Cis and Trans
In lecture today, we talked about the difference between cis and trans molecules. I understand the difference, but is it better for a molecule to be cis or trans?
- Sun Nov 04, 2018 3:46 pm
- Forum: Lewis Structures
- Topic: Exceptions to the Octet Rule
- Replies: 4
- Views: 299
Re: Exceptions to the Octet Rule
Atoms in period 3 or higher are exceptions to the octet rule because they have d-orbitals which can accommodate more electrons.
- Sun Nov 04, 2018 3:39 pm
- Forum: Sigma & Pi Bonds
- Topic: sigma and pi bonds
- Replies: 2
- Views: 324
Re: sigma and pi bonds
No, I do not believe that sigma and pi bonds will be on the midterm
- Sun Nov 04, 2018 3:32 pm
- Forum: Octet Exceptions
- Topic: Lewis acids and bases
- Replies: 3
- Views: 420
Lewis acids and bases
What are some other examples of Lewis acids and bases other than the examples from lecture?
- Sun Nov 04, 2018 3:18 pm
- Forum: Resonance Structures
- Topic: resonance structures for the test
- Replies: 2
- Views: 322
Re: resonance structures for the test
On the test, I'm assuming if a questions asks for the resonance structures, then you would draw all of the possible resonance structures.
- Tue Oct 23, 2018 3:25 pm
- Forum: Properties of Light
- Topic: How many photons
- Replies: 3
- Views: 305
Re: How many photons
Thank you!
- Tue Oct 23, 2018 3:24 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger Equation
- Replies: 3
- Views: 1631
Re: Schrodinger Equation
Thank you for your responses!
- Fri Oct 19, 2018 6:16 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger Equation
- Replies: 3
- Views: 1631
Schrodinger Equation
Hi,
Since we do not need to know how to do any calculations using Schrodinger's equation, does anyone know what we should know about it for the test next week?
Thank you
Since we do not need to know how to do any calculations using Schrodinger's equation, does anyone know what we should know about it for the test next week?
Thank you
- Fri Oct 19, 2018 6:13 pm
- Forum: Properties of Light
- Topic: How many photons
- Replies: 3
- Views: 305
How many photons
Hi,
Problem 1B.9 on the homework says:
A lamp rated at 32 W emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s?
Can someone please explain how to find the number of photons of light that can be generated?
Thank you
Problem 1B.9 on the homework says:
A lamp rated at 32 W emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s?
Can someone please explain how to find the number of photons of light that can be generated?
Thank you
- Thu Oct 04, 2018 5:34 pm
- Forum: Empirical & Molecular Formulas
- Topic: HW 1 Problem F.9
- Replies: 7
- Views: 472
Re: HW 1 Problem F.9
Yes, the ratio of the atoms would be the empirical formula.
- Thu Oct 04, 2018 5:17 pm
- Forum: Empirical & Molecular Formulas
- Topic: Question F9
- Replies: 5
- Views: 493
Re: Question F9
I would answer the question in a ratio and a formula just to be safe. The question does just ask for the ratio, but better safe than sorry.
- Thu Oct 04, 2018 4:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 408752
Re: Advice from a Medical Student [ENDORSED]
Thank you so much for the advice! As a pre-med student, it is very nice to hear that this course will be helpful for the MCAT and medical school. I will make sure to go to as many office hours and review sessions as I can in order to succeed in this course. Thank you again for your advice!