## Search found 59 matches

Wed Mar 13, 2019 5:19 pm
Forum: First Order Reactions
Topic: pseudo first order [ENDORSED]
Replies: 5
Views: 528

### 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: 332

### 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: 56

### 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: 89

### 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: 115

### 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: 98

### 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: 169

### 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: 407

### 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: 136

### 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: 105

### 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: 116

### 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: 283

### 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: 263

### 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: 165

### 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: 133

### 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: 176

### 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: 123

### 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: 92

### 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)
Mon Feb 25, 2019 1:34 pm
Forum: Balancing Redox Reactions
Topic: Adding H+, OH- and H20
Replies: 4
Views: 306

### 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: 158

### 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: 168

### 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: 148

### 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: 120

### 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: 102

### 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: 92

### 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: 150

### 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: 67

### 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: 115

### 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: 154

### 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: 73

### 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: 244

### 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: 172

### 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: 273

### 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: 95

### 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: 145

### 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: 174

### 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: 174

### 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: 133

### 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: 474

### 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: 133

### 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: 115

### 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: 57

### 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: 229

### 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: 129

### 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: 229

### 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: 84

### Hybridization

When does hybridization occur?
Mon Nov 26, 2018 5:53 pm
Forum: Sigma & Pi Bonds
Topic: Pi bonds
Replies: 4
Views: 430

### 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: 372

### 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: 91

### 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: 144

### 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: 175

### 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: 126

### 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: 142

### Re: How many photons

Thank you!
Tue Oct 23, 2018 3:24 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 3
Views: 322

### Re: Schrodinger Equation

Thank you for your responses!
Fri Oct 19, 2018 6:16 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 3
Views: 322

### 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
Fri Oct 19, 2018 6:13 pm
Forum: Properties of Light
Topic: How many photons
Replies: 3
Views: 142

### 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
Thu Oct 04, 2018 5:34 pm
Forum: Empirical & Molecular Formulas
Topic: HW 1 Problem F.9
Replies: 7
Views: 215

### 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: 237

### 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: 212
Views: 115064

### 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!

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