Search found 61 matches
- Sat Mar 16, 2019 7:55 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Transition State
- Replies: 3
- Views: 390
Re: Transition State
They are the highest points on the reaction profiles
- Sat Mar 16, 2019 7:52 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Catalyst in rate law?
- Replies: 6
- Views: 8181
Re: Catalyst in rate law?
Catalysts can be in the overall rate law. See Lyndon's Pork Ramen review question 14f for an example
- Sat Mar 16, 2019 7:49 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy
- Replies: 3
- Views: 690
Re: Entropy
According to the 2nd law, n a reversible process the total entropy of a system plus its surrounding is unchanged. delta Suniv = 0
- Sat Mar 16, 2019 7:40 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 374390
Re: Final Jitters
Something as simple as focusing on each breath slowly going in and out works wonders
- Sat Mar 16, 2019 7:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximation
- Replies: 7
- Views: 1288
Re: Approximation
Matthew Casillas 1C wrote:Are we allowed to approximate below 10^-4 or 10^-3?
I think I heard 10^-3
- Sun Mar 10, 2019 5:24 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximation
- Replies: 7
- Views: 1288
Approximation
When can we use the approximation that allows us to bypass calculating a quadratic?
- Tue Mar 05, 2019 1:21 pm
- Forum: Balancing Redox Reactions
- Topic: reduction potentials at pH =7
- Replies: 2
- Views: 411
Re: reduction potentials at pH =7
Which problem exactly are you referring to?
- Tue Mar 05, 2019 1:19 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7161
Re: Study Advice
The study sessions are great, you'd probably find value in any of the ones you attend but I wouldn't rely solely on review sessions. You should also do homework problems and read the book to fully understand what is going on in class.
- Tue Mar 05, 2019 1:17 pm
- Forum: General Rate Laws
- Topic: Unique Rate
- Replies: 4
- Views: 418
Unique Rate
What does the unique rate measure?
- Tue Mar 05, 2019 1:12 pm
- Forum: First Order Reactions
- Topic: Integrating
- Replies: 3
- Views: 405
Re: Integrating
Here's the link to the integration rules: https://lavelle.chem.ucla.edu/wp-conten ... _Rules.pdf
- Sun Feb 24, 2019 8:53 pm
- Forum: Balancing Redox Reactions
- Topic: Hydrogen?
- Replies: 3
- Views: 315
Re: Hydrogen?
Noah Cook 3O wrote:Generally hydrogen is not reduced or oxidized, but has a consistent oxidation state of +1. If it is a complex molecule that involves hydrogen, like H2SO4, it is usually another element within the molecule that is being reduced or oxidized.
Why is this?
- Sun Feb 24, 2019 8:51 pm
- Forum: Balancing Redox Reactions
- Topic: platinum
- Replies: 7
- Views: 700
Re: platinum
What's the point of adding platinum to the cell diagram?
- Sun Feb 24, 2019 8:48 pm
- Forum: Student Social/Study Group
- Topic: How are you guys going to study for Test 2?
- Replies: 10
- Views: 1023
Re: How are you guys going to study for Test 2?
I'd look at all the topics listed on the syllabus under electrochemistry and go through them one by one to make sure you understand each (at least up to what we need to know for the test).
- Sun Feb 17, 2019 10:30 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3641794
Re: Post All Chemistry Jokes Here
What did one charged atom say to the other? I’ve got my ion you.
- Sun Feb 17, 2019 10:18 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy Fundamentals
- Replies: 1
- Views: 231
Re: Gibbs Free Energy Fundamentals
the reaction is at equilibrium
- Sun Feb 17, 2019 10:13 am
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm Grades
- Replies: 35
- Views: 2787
Re: Midterm Grades
Based off of the time it took last quarter, we can expect them by next Friday the 22nd after lecture.
- Mon Feb 11, 2019 11:20 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: cooling a system
- Replies: 3
- Views: 390
Re: cooling a system
It may help to think of heat as a reactant/product. For example, in an endothermic reaction, heat would be a "reactant" which means cooling would decrease the amount of reactants and therefore the formation of reactants would be favored.
- Mon Feb 11, 2019 11:13 am
- Forum: Administrative Questions and Class Announcements
- Topic: Textbook glitch
- Replies: 2
- Views: 338
Re: Textbook glitch
Have you tried reloading it?
- Mon Feb 11, 2019 11:10 am
- Forum: Student Social/Study Group
- Topic: Too cute
- Replies: 5
- Views: 1234
Re: Too cute
This was so adorable
- Sun Feb 03, 2019 5:13 pm
- Forum: Phase Changes & Related Calculations
- Topic: Work by expansion
- Replies: 3
- Views: 374
Re: Work by expansion
1 l atm = 101.33 J, this is on the formula sheet
- Sun Feb 03, 2019 5:08 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity of Exo and Endo reactions
- Replies: 4
- Views: 931
Re: Spontaneity of Exo and Endo reactions
Yes but not all spontaneous reactions are exothermic.
- Sat Feb 02, 2019 3:32 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Absorbing and Releasing Heat
- Replies: 2
- Views: 2067
Re: Absorbing and Releasing Heat
For two objects at different temperatures, the hotter one will lose heat to the cooler one until they attain thermal equilibrium - i.e they have the same temperature. Assuming there is no heat lost to the surroundings, the total energy lost by the hotter one is equal to the energy gained by the cool...
- Sun Jan 27, 2019 5:31 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 1
- Views: 183
Re: Heat Capacity
Intensive property because it's defined as "heat required to raise the temperature of 1 mole of substance by 1 degree Celsius." and that doesn't change depending on the amount of substance there is because it is specifically referring to one mole.
- Sun Jan 27, 2019 5:22 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Factors related to acidity
- Replies: 2
- Views: 287
Re: Factors related to acidity
"Recall that electronegativity is the measure of an atom's attraction for electrons. The higher the electronegativity, the greater the attraction. We can extend this idea further and conclude that atoms with higher electronegativity will be less inclined to share their electrons with a proton. ...
- Sun Jan 27, 2019 5:20 pm
- Forum: Ideal Gases
- Topic: Calculating partial pressure
- Replies: 4
- Views: 408
Re: Calculating partial pressure
What problem are you referring to?
- Sun Jan 20, 2019 5:13 pm
- Forum: Lewis Acids & Bases
- Topic: Identifying Acids and Bases
- Replies: 5
- Views: 741
Re: Identifying Acids and Bases
Karyn Nguyen 1K wrote:What acids and bases (strong and weak) would be helpful to memorize?
Memorize all strong acids and bases (there aren't that many). Then you will know that all other acids/bases are weak.
- Sun Jan 20, 2019 5:12 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: K vs. Q
- Replies: 5
- Views: 4098
Re: K vs. Q
It is also important to note that Q can be equal to K. In this case, the reaction is at equilibrium.
- Sun Jan 20, 2019 5:09 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strength and Weakness
- Replies: 12
- Views: 1126
Re: Strength and Weakness
Compare their K values. The larger the value of Ka, the stronger the acid.
- Sun Jan 13, 2019 4:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solids in calculating equilibrium constant? [ENDORSED]
- Replies: 8
- Views: 870
Re: solids in calculating equilibrium constant? [ENDORSED]
No, pure solids and liquids are excluded in the calculation
- Sun Jan 13, 2019 4:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Criteria
- Replies: 4
- Views: 353
Re: Equilibrium Criteria
If you calculate Q and it is equal to K, the reaction is at equilibrium.
- Sun Jan 13, 2019 4:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: constants
- Replies: 4
- Views: 355
Re: constants
Kc is the equilibrium constant in terms of concentration, Kp is the equilibrium constant in terms of pressure, and Q is the reaction quotient which can be equal to K.
- Sat Dec 08, 2018 12:01 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: acids and bases
- Replies: 3
- Views: 360
Re: acids and bases
Yes you should memorize the strong acids so if you are asked to determine if an acid is strong or weak, you will know the answer based on if it's an acid you have memorized.
- Thu Dec 06, 2018 11:14 pm
- Forum: Amphoteric Compounds
- Topic: Lewis Structures and Amphoteric Compounds
- Replies: 1
- Views: 232
Lewis Structures and Amphoteric Compounds
How can you tell if a compound is amphoteric based on its Lewis structure?
- Wed Dec 05, 2018 6:44 pm
- Forum: Naming
- Topic: sodium bisoxalato(diaqua)ferrate(III)
- Replies: 1
- Views: 278
Re: sodium bisoxalato(diaqua)ferrate(III)
And why is oxalate named first when alphabetically it comes after aqua?
- Wed Dec 05, 2018 6:39 pm
- Forum: Naming
- Topic: sodium bisoxalato(diaqua)ferrate(III)
- Replies: 1
- Views: 278
sodium bisoxalato(diaqua)ferrate(III)
What's the significance of the parentheses around diaqua?
- Wed Dec 05, 2018 6:34 pm
- Forum: Naming
- Topic: OH2 vs H2O
- Replies: 5
- Views: 535
Re: OH2 vs H2O
If we write H2O when OH2 is in the answer, is it wrong?
- Wed Dec 05, 2018 9:53 am
- Forum: Amphoteric Compounds
- Topic: Amphoteric clarification
- Replies: 5
- Views: 555
Amphoteric clarification
An amphoteric compound can only act as an acid or a base at once, correct? It can't act as both at the same time right?
- Sat Dec 01, 2018 8:23 pm
- Forum: Hybridization
- Topic: 2SP^3 vs. SP^3
- Replies: 6
- Views: 801
Re: 2SP^3 vs. SP^3
2SP^3 is simply more specific than SP^3. They can mean the same thing.
- Tue Nov 27, 2018 11:14 pm
- Forum: Hybridization
- Topic: 2F.1
- Replies: 2
- Views: 212
2F.1
"State the relative orientations of each of the following hybrid orbitals" What is this question asking?
- Tue Nov 27, 2018 11:12 pm
- Forum: Hybridization
- Topic: S- Character
- Replies: 1
- Views: 224
S- Character
What is the s-character of a hybrid orbital and why does it increasing cause the bond angle to increase?
- Tue Nov 20, 2018 10:13 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.1
- Replies: 2
- Views: 149
2E.1
Why might option b have lone pairs? Wouldn't it look like option a if it had lone pairs?
- Sun Nov 18, 2018 10:13 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 7
- Views: 726
Re: Hydrogen Bonding
RoopshaChatterjee 1G wrote:How do we use the attractive energy to determine the structure of the molecule?
Are you sure attractive energy matters when determining the structure of a molecule?
- Sun Nov 18, 2018 10:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: molecular shapes
- Replies: 13
- Views: 976
Re: molecular shapes
KarlaArevalo4D wrote:I think we might (should) get like the general shapes and structures on the formula sheet, at least that is what a past chem prof. gave us not to sure
The formula sheet is posted online and doesn't have any of the shapes on it
- Sun Nov 18, 2018 10:07 am
- Forum: Ionic & Covalent Bonds
- Topic: Contribution to the resonance structure?
- Replies: 3
- Views: 455
Re: Contribution to the resonance structure?
But what exactly does it mean to contribute to a resonance structure?
- Sun Nov 11, 2018 4:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 7
- Views: 726
Re: Hydrogen Bonding
What does the attractive energy measure?
- Sun Nov 11, 2018 4:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Van der Waals vs Dispersion Forces
- Replies: 8
- Views: 1179
Re: Van der Waals vs Dispersion Forces
London dispersion forces are a type of Van der Waal’s forces. These forces always operate in any substance. In general, the heavier the molecule, the stronger the Van der Waal's force of interaction. So the two terms aren't completely synonymous? A London dispersion force is a type of van de waal's...
- Sun Nov 11, 2018 4:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: molecular shapes
- Replies: 13
- Views: 976
Re: molecular shapes
Do we have to memorize the shapes or is there a method we can follow to draw the structure?
- Tue Oct 30, 2018 9:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.15
- Replies: 2
- Views: 303
2A.15
"Write the most likely charge for the ions formed by each of the following elements (a) S; (b) Te; (c) Rb; (d) Ga." How is this determined?
- Tue Oct 30, 2018 5:55 pm
- Forum: Lewis Structures
- Topic: kekule structure?
- Replies: 3
- Views: 297
Re: kekule structure?
Will we be tested on Kekule structures?
- Tue Oct 30, 2018 5:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 11
- Views: 931
Re: Midterm
Kunseo Yook 2E wrote:Are there going to be review sessions for the midterm?
Yes the review sessions have been emailed to us
- Tue Oct 30, 2018 5:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Peer Learning Sessions [ENDORSED]
- Replies: 10
- Views: 7882
Peer Learning Sessions [ENDORSED]
Will the step up sessions, workshops, and drop in sessions still happen at their normal times or have they been replaced by the midterm review sessions?
- Tue Oct 23, 2018 10:02 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 1D.25 Seventh Edition
- Replies: 2
- Views: 279
1D.25 Seventh Edition
Why can't the subshell 2d exist in an atom?
- Sun Oct 21, 2018 12:41 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg equation
- Replies: 4
- Views: 429
Re: Rydberg equation
Is this the equation Lavelle told us to steer away from using because students usually make mistakes?
- Sun Oct 21, 2018 12:29 am
- Forum: Einstein Equation
- Topic: Numbers to memorize [ENDORSED]
- Replies: 37
- Views: 4183
Re: Numbers to memorize [ENDORSED]
Do you know how many significant figures we should use when solving problems, or should we just match the given information? They are given on the exams but it might be helpful to familiarize yourself with some of the more frequently used constants just as a time saving technique. Match the given i...
- Sun Oct 21, 2018 12:27 am
- Forum: Einstein Equation
- Topic: Using Joules
- Replies: 2
- Views: 390
Re: Using Joules
Yes, it's used to cancel units
- Fri Oct 12, 2018 2:28 am
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Questions Due Date
- Replies: 7
- Views: 590
Re: Chemistry Community Questions Due Date
Does that mean they're due by Friday at 11:59pm?
- Fri Oct 12, 2018 2:20 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Balmer and Lyman series
- Replies: 3
- Views: 206
Re: Balmer and Lyman series
What do the ns signify in this equation?
- Fri Oct 12, 2018 2:19 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Balmer and Lyman series
- Replies: 4
- Views: 325
Balmer and Lyman series
Why are these important? What are they?
- Wed Oct 03, 2018 7:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grading for Chemistry Community [ENDORSED]
- Replies: 6
- Views: 836
Re: Grading for Chemistry Community [ENDORSED]
Max Kwon 1J wrote:Wait, so do you have to make 3 posts a week or are 3 replies fine?
I believe replies count as posts.
- Wed Oct 03, 2018 7:47 pm
- Forum: SI Units, Unit Conversions
- Topic: HW Question E1, when do we convert units?
- Replies: 1
- Views: 163
HW Question E1, when do we convert units?
In the solutions manual, the answer for question E1 from the homework was converted to kilometers. What wording in the question hints that I am supposed to convert units?
- Wed Oct 03, 2018 7:43 pm
- Forum: SI Units, Unit Conversions
- Topic: Textbook Homework Assignment
- Replies: 11
- Views: 1382
Re: Textbook Homework Assignment
sallina_yehdego wrote:Quick Question: Are we supposed to write down the questions for the textbook problems when doing the homework??
I don't remember anyone saying we had to write the question down.