Search found 62 matches
- Sun Feb 24, 2019 11:51 pm
- Forum: Balancing Redox Reactions
- Topic: E dependency on moles
- Replies: 2
- Views: 316
Re: E dependency on moles
If you think about the definition of an intensive property where the value does not depend on anything else (anything external), then you can see that anything with an intensive property won't depend on moles. E is an intensive property, so it checks out.
- Sun Feb 24, 2019 11:49 pm
- Forum: Balancing Redox Reactions
- Topic: Redox Rxns in Acidic and Basic Solutions
- Replies: 6
- Views: 502
Re: Redox Rxns in Acidic and Basic Solutions
The problem would have to tell us.
- Sun Feb 24, 2019 11:48 pm
- Forum: Environment, Fossil Fuels, Alternative Fuels
- Topic: Why energy crisis?
- Replies: 8
- Views: 4388
Re: Why energy crisis?
We can't use all forms of energy in the same way.
- Sun Feb 24, 2019 11:47 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Free Energy is a state function?
- Replies: 5
- Views: 610
Re: Free Energy is a state function?
The path doesn't affect the end value of free energy, so we can just add and subtract them up.
- Sun Feb 24, 2019 11:46 pm
- Forum: Van't Hoff Equation
- Topic: Test 2
- Replies: 3
- Views: 602
Re: Test 2
Just check the rest of outline 4 that we didn't cover on the midterm!
- Sun Feb 24, 2019 11:44 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous and unstable
- Replies: 4
- Views: 1508
Spontaneous and unstable
What's the difference between spontaneous and unstable?
- Sun Feb 24, 2019 11:44 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 3
- Replies: 14
- Views: 2301
Re: Test 3
Follow the outlines and do whatever is on the homework! That consistently works for me when I'm studying for tests.
- Sun Feb 24, 2019 11:43 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2
- Replies: 1
- Views: 264
Test 2
In the sixth edition of the textbook, what problems should we go up to for test 2? (When do the Nerst Equation problems start?
- Tue Feb 12, 2019 2:25 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 23123
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Mya Majewski 1L wrote:for question 8, isn't the answer going to be Kb x 3^8?
the formula is S=KblnW, so you need to take the natural log of 3 to the 8th power
- Tue Feb 12, 2019 1:54 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 23123
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
For #6, how do we know that work is equal to 0?
- Tue Feb 12, 2019 1:35 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 23123
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
I'm confused on #4, too. What equations are relevant?
- Sat Feb 09, 2019 12:20 pm
- Forum: Calculating Work of Expansion
- Topic: Derivatives and Integrals
- Replies: 5
- Views: 629
Derivatives and Integrals
Will we need to use derivatives and integrals on the midterm? Or did we just do that to derive the equations that we use now?
- Sat Feb 09, 2019 12:19 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Systems
- Replies: 6
- Views: 938
Systems
What's a quick way to know if something is open, closed, or isolated? It gets confusing.
- Sat Feb 09, 2019 12:18 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm
- Replies: 1
- Views: 257
Midterm
What homework problems should I go up to in outline 4 for the midterm if I'm using the sixth edition textbook? I know we stop before Gibb's Free Energy, but I'm not sure which homework problem that corresponds to.
- Wed Jan 30, 2019 11:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: increasing pressure, what happens to concentration?
- Replies: 10
- Views: 2478
Re: increasing pressure, what happens to concentration?
Take volume into account. The reaction will favor the side with fewer moles.
- Wed Jan 30, 2019 11:58 pm
- Forum: Ideal Gases
- Topic: derivatives and integrals
- Replies: 6
- Views: 986
Re: derivatives and integrals
He gave us two equations that were the same thing, just in different forms. The integral and the other equation mean the same thing; it's just different math.
- Wed Jan 30, 2019 11:56 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Properites
- Replies: 7
- Views: 614
Re: State Properites
When dealing with work and heat, you have to take into account every step in the process of the change, not just the final and initial values.
- Wed Jan 30, 2019 11:53 pm
- Forum: Phase Changes & Related Calculations
- Topic: J vs. kJ
- Replies: 9
- Views: 1023
Re: J vs. kJ
It shouldn't matter unless they specify! Make sure you know what the question is asking though.
- Wed Jan 30, 2019 11:52 pm
- Forum: Phase Changes & Related Calculations
- Topic: Week 4 Homework
- Replies: 12
- Views: 1223
Re: Week 4 Homework
It really depends on your TA, but to be safe, just do material that we learned this week or las week.
- Wed Jan 30, 2019 11:51 pm
- Forum: Phase Changes & Related Calculations
- Topic: Test #1
- Replies: 11
- Views: 952
Re: Test #1
Yes, we all get them back this week!
- Wed Jan 23, 2019 3:41 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Law
- Replies: 7
- Views: 722
Ideal Gas Law
When can we use the ideal gas law?
- Wed Jan 23, 2019 3:40 pm
- Forum: Phase Changes & Related Calculations
- Topic: How to tell acids and bases
- Replies: 8
- Views: 600
Re: How to tell acids and bases
In chem14a, we drew lewis dot structures, and through that, we saw if something was an acid or a base.
- Wed Jan 23, 2019 3:38 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic or Exothermic
- Replies: 20
- Views: 1976
Re: Endothermic or Exothermic
Condensation is exothermic because it releases heat. You see this in real life when you have a cold drink and condensation forms water droplets on the side of the cup.
- Tue Jan 15, 2019 3:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: test 1 [ENDORSED]
- Replies: 7
- Views: 891
Re: test 1 [ENDORSED]
The test will probably cover acids and bases, too. I think it will most likely cover lectures from the first two weeks.
- Tue Jan 15, 2019 3:32 pm
- Forum: General Science Questions
- Topic: Autoprotolysis
- Replies: 3
- Views: 657
Re: Autoprotolysis
If you break down the word into parts, you can deduce the meaning, too! Auto would indicate that autoprotolysis happens itself, hinting that it involves the same molecule. Proto can tell you that it involves protons.
- Tue Jan 15, 2019 3:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Changes to K value
- Replies: 9
- Views: 672
Re: Changes to K value
Only changes in temperature change the K value.
- Sun Jan 13, 2019 3:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Heterogeneous and homogeneous equilibria [ENDORSED]
- Replies: 8
- Views: 728
Re: Heterogeneous and homogeneous equilibria [ENDORSED]
We have to keep in mind if any of the reactants or products are solids or liquids because we don't factor them in when we calculate the equilibrium constant, K.
- Sun Jan 13, 2019 3:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: equations
- Replies: 10
- Views: 720
Re: equations
You can tell what are reactants or products if you know the equation for the chemical reaction. If the problem doesn't just straight out give it to you, you can figure it out yourself based on context clues from the problem.
- Sun Jan 13, 2019 3:56 pm
- Forum: Ideal Gases
- Topic: When to Use PV=nRT
- Replies: 8
- Views: 1620
Re: When to Use PV=nRT
For this class, I think we just need to use this equation when we convert from concentration to partial pressure, so when you are solving for Kc, you need concentrations and when you are solving for Kp, you need partial pressures.
- Wed Jan 09, 2019 10:27 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Difference between brackets and parentheses?
- Replies: 4
- Views: 2689
Re: Difference between brackets and parentheses?
Other answers explained the reasoning, but basically you use brackets when solving for Kc and use parentheses when solving for Kp.
- Wed Jan 09, 2019 10:25 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K
- Replies: 4
- Views: 297
Re: K
Kc is used when the units of the equilibrium concentrations are moles per liter. Kp is used when using partial pressure. It’s basically the same thing but with different units.
- Wed Jan 09, 2019 10:22 am
- Forum: Student Social/Study Group
- Topic: New to Lavelle
- Replies: 32
- Views: 5232
Re: New to Lavelle
I honestly find all of his resources helpful, so I do all the problems in the book, watch the modules, and go to workshops when I need extra help on a topic. That’s just generally how I prepare for a test in his class.
- Wed Dec 05, 2018 12:47 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelates
- Replies: 5
- Views: 529
Re: chelates
Chelates are in the shape of rings, making them pretty easy to distinguish.
- Wed Dec 05, 2018 12:46 am
- Forum: Naming
- Topic: Knowing oxidation states
- Replies: 11
- Views: 919
Re: Knowing oxidation states
I think it is safe to just study the sheet posted on Lavelle's website because it has a lot of common ligands that we should probably know.
- Mon Nov 26, 2018 11:18 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone PR and Bonding PR
- Replies: 2
- Views: 240
Lone PR and Bonding PR
Which lone pair and bonding pair shapes do we need to know? I know there are bent and trigonal pyramidal, but which other ones would we need to know for test 3?
- Mon Nov 26, 2018 11:27 am
- Forum: Bond Lengths & Energies
- Topic: How to Measure Bond Lengths
- Replies: 4
- Views: 526
Re: How to Measure Bond Lengths
We only need to know the trends, not the exact bond lengths.
- Mon Nov 26, 2018 11:26 am
- Forum: Dipole Moments
- Topic: dipole
- Replies: 6
- Views: 546
Re: dipole
Dipoles can cancel each other out so the molecule would not be polar.
- Mon Nov 26, 2018 11:25 am
- Forum: Coordinate Covalent Bonds
- Topic: Coordinate Covalent Bond Definition
- Replies: 14
- Views: 1818
Re: Coordinate Covalent Bond Definition
That definition seems correct. It's basically identical to the one from lecture today!
- Mon Nov 26, 2018 11:23 am
- Forum: Naming
- Topic: Naming and Polyatomic Ions
- Replies: 6
- Views: 999
Re: Naming and Polyatomic Ions
im pretty sure you can use them interchangeably
Re: Naming
bond angles for pentagona bipyramidal are 72 and 90 degrees
Re: Naming
ions are charged
- Thu Nov 15, 2018 2:20 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: 11
- Views: 968
Re: hydrogen bonding
Hydrogen bonding takes more energy to break because it is stronger than most intermolecular forces.
- Thu Nov 15, 2018 2:18 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: Polar and Dipole
- Replies: 3
- Views: 246
Polar and Dipole
What's the relationship between polarization and dipole moments? What's the difference?
- Thu Nov 15, 2018 2:17 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi bonds
- Replies: 4
- Views: 699
Sigma and Pi bonds
How do we figure out if i bond is a sigma bond or a pi bond?
- Wed Nov 07, 2018 3:06 pm
- Forum: Dipole Moments
- Topic: HCl
- Replies: 6
- Views: 556
Re: HCl
HCl has a permanent dipole moment because H becomes slightly positive because it gives its electron to Cl which becomes slightly negative.
- Wed Nov 07, 2018 3:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: Metalloids
- Replies: 2
- Views: 277
Metalloids
What type of bonds do metalloids form?
- Wed Nov 07, 2018 3:04 pm
- Forum: Octet Exceptions
- Topic: List of octect exceptions
- Replies: 6
- Views: 656
List of octect exceptions
Can someone provide a brief, undetailed list of the octet exceptions we have learned so far?
- Thu Nov 01, 2018 3:26 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 8
- Views: 941
Re: Resonance
Double bonds are stronger than single bonds and require more energy to break. Triple bonds are stronger than double bonds. They all have different lengths because they have different strengths.
- Thu Nov 01, 2018 3:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Bonds
- Replies: 16
- Views: 1573
Re: Covalent Bonds
Non metals cannot form cations; instead, they form anions and metals form cations.
- Thu Nov 01, 2018 3:22 pm
- Forum: Ionic & Covalent Bonds
- Topic: Removing the second electron
- Replies: 8
- Views: 659
Re: Removing the second electron
Removing the second electron is a lot harder because of the net charge of the atom becomes more positive after removing the first electron, so removing the second electron requires more energy.
- Mon Oct 22, 2018 4:24 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Test 2
- Replies: 2
- Views: 227
Test 2
Do we need to know electron configurations for test 2?
- Mon Oct 22, 2018 4:22 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Ionization
- Replies: 1
- Views: 154
Ionization
What does ionization mean exactly?
- Mon Oct 22, 2018 4:21 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Test 2 and Homework Problems
- Replies: 6
- Views: 652
Test 2 and Homework Problems
I've been doing the homework problems, but I don't think some of the homework problems for the Quantum World will be on the test just yet. I think all the homework problems up to 2.41 in the sixth edition can be on the test, but everything after will not (2.45-2.93). Can someone double check this?
- Tue Oct 16, 2018 5:38 pm
- Forum: DeBroglie Equation
- Topic: Equations
- Replies: 9
- Views: 807
Re: Equations
We get an equation sheet for most of the relevant equations, like we did during AP exams.
- Tue Oct 16, 2018 5:37 pm
- Forum: Properties of Light
- Topic: Mass of Light
- Replies: 5
- Views: 619
Re: Mass of Light
Light does not have a rest mass, so you can't calculate the mass of light.
- Tue Oct 16, 2018 5:35 pm
- Forum: Properties of Light
- Topic: Threshold Energy
- Replies: 4
- Views: 168
Re: Threshold Energy
The electron is still removed, but it just does not have kinetic energy.
- Mon Oct 08, 2018 12:42 pm
- Forum: SI Units, Unit Conversions
- Topic: E23 (6th Edition)
- Replies: 4
- Views: 282
Re: E23 (6th Edition)
You don't need to use avogadro's number in this problem because it says calculate in moles.
- Mon Oct 08, 2018 11:46 am
- Forum: SI Units, Unit Conversions
- Topic: HW E.9
- Replies: 3
- Views: 379
Re: HW E.9
We'll be given the formulas, so we don't need to know them by name. We just need to focus on the concepts he lectured on for the first test.
- Mon Oct 08, 2018 11:44 am
- Forum: SI Units, Unit Conversions
- Topic: Homework for Week 2
- Replies: 16
- Views: 1002
Homework for Week 2
Does the homework for week 2 need to be problems about the quantum world? Can we still do problems from fundamentals for homework this week?
- Sun Sep 30, 2018 10:32 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mutiplying by a number
- Replies: 3
- Views: 247
Re: Mutiplying by a number
You can multiply it by 100 to get an integer and then divide by the greatest common factor to be super exact, but just rounding it would most likely be better.
- Sun Sep 30, 2018 10:26 pm
- Forum: Balancing Chemical Reactions
- Topic: Short cuts/methods for balancing equations
- Replies: 15
- Views: 1654
Re: Short cuts/methods for balancing equations
Try to take it one element at a time. Write out how many of each element there is in the reactants and do the same for the products. Then, add coefficients where necessary. It's easiest taking it step by step.
- Sun Sep 30, 2018 10:21 pm
- Forum: SI Units, Unit Conversions
- Topic: Unit Conversions
- Replies: 4
- Views: 504
Re: Unit Conversions
Remembering conversions generally just happens over time with practice through homework and classwork problems. To convert from g to kg, divide by 1000.