## Search found 61 matches

Sat Mar 16, 2019 7:55 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Transition State
Replies: 3
Views: 61

### 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: 331

### 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: 242

### 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: 96
Views: 19950

### 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: 152

### 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: 152

### 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: 98

### 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: 31
Views: 654

### 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: 104

### Unique Rate

What does the unique rate measure?
Tue Mar 05, 2019 1:12 pm
Forum: First Order Reactions
Topic: Integrating
Replies: 3
Views: 81

### 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: 61

### 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: 110

### 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: 184

### 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: 7752
Views: 1070459

### 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: 61

### 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: 844

### 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: 91

### 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: 101

### 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: 615

### 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: 84

### 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: 99

### 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: 70

### 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: 41

### 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: 92

### 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: 120

### 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: 345

### 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: 210

### 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: 314

### 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: 184

### 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: 89

### 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: 100

### 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: 103

### 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: 37

### 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: 46

### 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: 46

### 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: 121

### 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: 152

### 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: 135

### 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: 62

### 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: 59

### 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: 31

### 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: 164

### 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: 280

### 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: 153

### 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: 164

### 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: 217

### 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: 280

### 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: 87

### 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: 86

### 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: 286

### 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: 6709

### 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: 91

### 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: 133

### 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: 1130

### 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: 149

### 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: 150

### 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: 95

### 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: 100

### 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: 263

### 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: 92

### 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: 586

### 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.

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