## Search found 64 matches

Sat Mar 16, 2019 1:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H
Replies: 7
Views: 688

### Re: Delta H

Milena Aragon 2B wrote:
Ashley P 4I wrote:Because it is a state function, it means that you can add/subtract two different delta H’s correct?

Yes, if you're asked to find the total enthalpy change you can add/subtract enthalpy values from multiple reactions

Thank you so much!
Sat Mar 16, 2019 1:26 pm
Forum: Student Social/Study Group
Topic: Solutions for Tests 1 and 2
Replies: 7
Views: 593

### Re: Solutions for Tests 1 and 2

Marina Gollas 1A wrote:
Ashley P 4I wrote:I believe that test one is posted but not test two.

Where is test 1 posted at?

Sorry I got confused with the posting of the midterm. I went to a review session and she went over questions on test one but only for the Friday session.
Sat Mar 16, 2019 1:23 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H
Replies: 7
Views: 688

### Re: Delta H

Because it is a state function, it means that you can add/subtract two different delta H’s correct?
Sat Mar 16, 2019 1:21 pm
Forum: General Rate Laws
Topic: Unique Reaction Rates [ENDORSED]
Replies: 33
Views: 77957

### Re: Unique Reaction Rates[ENDORSED]

riddhiduggal wrote:When do we use the instantaneous rate versus the unique rates?

I am also still really confused on this. If I find out, I’ll let you know.
Sat Mar 16, 2019 1:10 pm
Forum: Student Social/Study Group
Topic: Solutions for Tests 1 and 2
Replies: 7
Views: 593

### Re: Solutions for Tests 1 and 2

I believe that test one is posted but not test two.
Sat Mar 16, 2019 1:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Past Finals
Replies: 4
Views: 469

### Re: Past Finals

Alexa_Henrie_1I wrote:If you google "Bruin Test Bank at UCLA" and click the Chemistry tab, there is a 14B final from Lavelle's Winter 2014 class.

You are a life savor!!!
Sat Mar 16, 2019 1:05 pm
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12683

Ashley P 4I wrote:Is there any worksheets for kinetics?

Nevemind I just found them, thank you for your help! Do you by chance have a final practice test? Or does anyone else have one?
Sat Mar 16, 2019 12:55 pm
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12683

Is there any worksheets for kinetics?
Sat Mar 16, 2019 12:43 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Ice melting
Replies: 4
Views: 395

### Re: Ice melting

There was a question on Test Two about dry ice being left in a room at room temperature. Would that also be a spontaneous reaction? Because it is moving towards becoming vaporized?
Sat Mar 16, 2019 12:37 pm
Forum: Second Order Reactions
Topic: 2nd order rates
Replies: 6
Views: 347

### Re: 2nd order rates

Yes. In order to get overall order, you simply add the powers of the reactants--so, two reactants of first order will form a second order rate law for the overall reaction. Thank you! I’m actually starting to understand this. Thanks to your comment. Do you think we will be expected to know 3rd orde...
Sat Mar 16, 2019 12:32 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: k & K
Replies: 18
Views: 813

### Re: k & K

Melissa Villanueva1K wrote:Will there be a clear indication of 'k' and 'K' on the final? Such as bolding one over the other. Thanks.

Do you mean on the constants and equations sheet?
Sat Mar 16, 2019 12:30 pm
Forum: General Rate Laws
Topic: Final
Replies: 9
Views: 468

### Re: Final

Just stay on the safe side and make a mental note of what needs units and what doesn’t. Like in equilibrium they cancel out.
Sat Mar 16, 2019 12:29 pm
Forum: General Rate Laws
Topic: Final
Replies: 9
Views: 468

### Re: Final

I went to a review session and the TA said to really be careful with units. It could mark you down quite a bit.
Fri Mar 15, 2019 9:55 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: What is pKa and Ka exactly?
Replies: 11
Views: 9065

### Re: What is pKa and Ka exactly?

the smaller the Ka, the weaker the acid
Fri Mar 15, 2019 9:52 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic and Endothermic Reactions
Replies: 4
Views: 474

### Re: Exothermic and Endothermic Reactions

If the temperature is ^ endothermic process will be favored. If the temperature is -, the exothermic process is favored.
Fri Mar 15, 2019 9:50 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Units
Replies: 6
Views: 474

### Re: Units

There are no units because they cancel out.
Fri Mar 15, 2019 9:49 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa vs. pH
Replies: 15
Views: 2228

### Re: pKa vs. pH

pKa= -log of Ka
pH stand= -log of Hydronium ions.
Fri Mar 15, 2019 9:48 am
Forum: Ideal Gases
Topic: How do I know what is an Ideal Gas
Replies: 11
Views: 350

### Re: How do I know what is an Ideal Gas

We are supposed to assume the gases in the questions are ideal gases.
Fri Mar 15, 2019 9:46 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 14
Views: 328

### Re: Anode and Cathode

I thought if the E knot was negative then the cathode would be on the right?
Fri Mar 15, 2019 9:40 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Reducing/Oxidizing Power
Replies: 7
Views: 391

### Re: Reducing/Oxidizing Power

Positive E value = higher oxidizing power
Negative E value = higher reducing power
Fri Mar 15, 2019 9:39 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Reducing/Oxidizing Power
Replies: 7
Views: 391

### Re: Reducing/Oxidizing Power

Positive E value = higher oxidizing power
Negative E value = higher reducing power
Fri Mar 15, 2019 9:38 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2: Melting Ice
Replies: 6
Views: 448

### Re: Test 2: Melting Ice

Is this the case with the sublimation of dry ice as well?
Fri Mar 15, 2019 9:32 am
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Mid term
Replies: 2
Views: 650

### Re: Mid term

There was also a couple on acids/bases.
Fri Mar 15, 2019 9:29 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Meaning of E
Replies: 3
Views: 255

### Re: Meaning of E

E knot is standard.
Fri Mar 15, 2019 9:26 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Galvanic Cells
Replies: 4
Views: 211

### Re: Galvanic Cells

It stops working because it reaches equilibrium.
Fri Mar 15, 2019 9:21 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2
Replies: 4
Views: 230

### Re: Test 2

Can anyone explain why precipitation causes delta G to decrease?
Fri Mar 15, 2019 9:19 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2, Question 6 part a
Replies: 4
Views: 201

### Re: Test 2, Question 6 part a

You could also look at this by looking at electronegativity. The more electronegative it is the reducing agent and it itself is being oxidized.
Thu Feb 21, 2019 7:34 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Midterm #1 14B
Replies: 17
Views: 992

### Re: Midterm #1 14B

What TA's review sessions did y'all find to be the most helpful? Because I've gone to a few where I feel more lost when I leave then helped.
Thu Feb 21, 2019 7:34 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Midterm #1 14B
Replies: 17
Views: 992

### Re: Midterm #1 14B

What TA's review sessions did y'all find to be the most helpful? Because I've gone to a few where I feel more lost when I leave then helped.
Thu Feb 21, 2019 7:32 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: HW 9.25: Understanding Molor disorder of crystals
Replies: 4
Views: 767

### Re: HW 9.25: Understanding Molor disorder of crystals

Do we multiply avrogados number by the amount of forms?
Thu Feb 21, 2019 7:31 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: HW 9.25: Understanding Molor disorder of crystals
Replies: 4
Views: 767

### Re: HW 9.25: Understanding Molor disorder of crystals

Do we multiply avrogados number by the amount of forms?
Thu Feb 21, 2019 7:28 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 7th edition 4I. 5
Replies: 3
Views: 182

### Re: 7th edition 4I. 5

Does anyone know what equation this is on the 6th edition?
Thu Feb 21, 2019 7:25 am
Forum: Environment, Fossil Fuels, Alternative Fuels
Topic: midterm
Replies: 3
Views: 497

### Re: midterm

For future reference there was questions on the midterm related photosynthesis and ATP hydrolysis on the midterm. Both of which involve the environment.
Sun Jan 20, 2019 7:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium and Disassociation of a Diatomic Molecule (11.7)
Replies: 4
Views: 2171

### Re: Equilibrium and Disassociation of a Diatomic Molecule (11.7)

So x^2 is derived from the ice table? Is it like a short hand? Or is it a different formula?
Wed Dec 05, 2018 11:23 pm
Forum: Naming
Topic: Polyatomic ions and naming
Replies: 7
Views: 212

### Re: Polyatomic ions and naming

Does anyone know the pages for the this in the 6th edition?
Wed Dec 05, 2018 11:22 pm
Forum: Naming
Topic: Tricks/cheat sheet
Replies: 3
Views: 206

### Re: Tricks/cheat sheet

There's a video by Mr.Causey called Naming compounds in Chemistry and he goes over roots and has cheat sheets you can use to remember what he teaches in the videos. It's old but it gets the job done.
Wed Dec 05, 2018 11:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 38
Views: 1191

### Re: Test 3

Angela Grant 3G wrote:
Ashley P 4I wrote:Does anyone have a trick to memorizing all these things?

I made a big chart to study off of, you can find one online if you just search up VSEPR geometries

Thank you so much! I ended up making flash cards as well.
Wed Dec 05, 2018 11:11 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka and Kb on Final
Replies: 9
Views: 2198

### Re: Ka and Kb on Final

I am also very confused on this because todays lecture talked more about 14B rather than what we would need to learn in terms of this course.
Wed Dec 05, 2018 11:09 pm
Forum: Lewis Acids & Bases
Topic: Textbook section on acids
Replies: 3
Views: 179

### Re: Textbook section on acids

amogha_koka3I wrote:Does anyone know what the above sections correspond to in the 7th edition.

Were you able to find it?
Wed Dec 05, 2018 11:07 pm
Forum: Lewis Acids & Bases
Topic: Difference between Lewis and Bronsted
Replies: 5
Views: 271

### Re: Difference between Lewis and Bronsted

How do we identify the difference then? Like is there a specific way of knowing the difference or do we need to memorize?
Wed Dec 05, 2018 11:06 pm
Forum: Lewis Acids & Bases
Topic: How to Identify Lewis acid and Bases
Replies: 4
Views: 562

### Re: How to Identify Lewis acid and Bases

You two are life savers, thank you for simplifying this. Lone Pairs= Base No lone pairs= Acid
Tue Nov 27, 2018 6:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Lone Pairs Affecting Bond Angles/Shape?
Replies: 4
Views: 379

### Re: Lone Pairs Affecting Bond Angles/Shape?

Lone pairs decrease bong angles. Got it. Thank you!!
Tue Nov 27, 2018 6:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 38
Views: 1191

### Re: Test 3

Does anyone have a trick to memorizing all these things?
Tue Nov 27, 2018 6:11 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Happy Lavelle [ENDORSED]
Replies: 5
Views: 775

### Re: Happy Lavelle[ENDORSED]

He literally is always smiling! I love his jokes, genuinely makes my day.
Tue Nov 27, 2018 6:09 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation
Replies: 2
Views: 138
Thank you for explaining, I couldn't quite understand it in lecture.
Sun Nov 11, 2018 4:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR?
Replies: 9
Views: 383

### Re: VSEPR?

Roni Touboul wrote:Why is VSEPR important for drawing lewis structures?

If I'm not mistaken, I believe its the opposite way around. Lewis dot structures are important for drawing/understanding VSEPR. Lewis dot structures lead us to find the structure of these components.
Sun Nov 11, 2018 4:33 pm
Forum: Resonance Structures
Topic: Bond Lengths
Replies: 7
Views: 386

### Re: Bond Lengths

There was a question like this on the midterm and I'm still lost on how to do it. Can someone please explain how to even calculate bond lengths? Is there like a number we need to attribute to double and single bonds thats universal?
Sun Nov 11, 2018 4:30 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 13
Views: 2800

### Re: Formal Charge Equation

Jasmin Argueta 1K wrote:The shortcuts my PLF taught me was FC=sticks+dots around the molecule

I love how simple this is\. Thank you for putting this on here. Do we count the sticks as having two electrons or just counting the litiral sticks?
Thu Nov 01, 2018 4:14 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm study
Replies: 7
Views: 389

### Re: Midterm study

We should make a massive group me. We had one for my LS 30 courses and it worked amazingly!
Thu Nov 01, 2018 4:12 pm
Forum: Ionic & Covalent Bonds
Topic: 6th Edition, Question 3.5
Replies: 3
Views: 180

### Re: 6th Edition, Question 3.5

I personally just remember that 3d goes before 4p and just subtract or add the one in the outer shell. I don't know if that the proper way, but I seem to get it right each time.
Thu Nov 01, 2018 3:56 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Chlorine and Oxidation States
Replies: 5
Views: 2813

### Re: Chlorine and Oxidation States

So from my understanding you just need to go to the previous and next noble gas? I am still confused.
Sun Oct 28, 2018 10:40 pm
Forum: Ionic & Covalent Bonds
Topic: Good practice options for lewis structures?
Replies: 3
Views: 171

### Re: Good practice options for lewis structures?

Y’all are amazing, thanks for the extra help!!
Sun Oct 28, 2018 10:36 pm
Forum: Ideal Gases
Replies: 147
Views: 104699

I feel like going to lecture and understanding the main concepts in class first helps me better understand the book. For test prep, I do homework problems and I use the module questions. If you don’t understand a question on the modules, look it up on chemistry community! It more than likely has alr...
Thu Oct 25, 2018 11:24 pm
Forum: Photoelectric Effect
Topic: How to calculate the kinetic energy, energy and frequency? [ENDORSED]
Replies: 20
Views: 4314

### Re: How to calculate the kinetic energy, energy and frequency?[ENDORSED]

At last I finally understood what this problem was asking, thank you so much!
Sat Oct 20, 2018 9:02 am
Topic: Black Body
Replies: 10
Views: 686

### Re: Black Body

The professor said we do not need to know this for this course (14a) but might for later courses.
Fri Oct 19, 2018 11:32 pm
Forum: SI Units, Unit Conversions
Topic: Remembering Unit Conversions
Replies: 5
Views: 444

### Re: Remembering Unit Conversions

Wait do we need to memorize these conversions? Do we also need to memorize the frequency conversions such as what one joule is in etc?
Fri Oct 19, 2018 11:29 pm
Forum: DeBroglie Equation
Topic: does everything have a wavelength
Replies: 10
Views: 640

### Re: does everything have a wavelength

Does anyone have the car problem the Professor used in order to explain this?
Sun Oct 14, 2018 11:03 am
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 5
Views: 541

### Re: Test 1

The tests were being graded immediately by my TA in my discussion. She had a 9 am discussion and she was almost done grading those. It might be best to email your TA and if you are really eager maybe they will let you see it during office hours (if those are before your dis section).
Sun Oct 14, 2018 11:00 am
Forum: Properties of Light
Topic: Car Example in Class with De Brogile Equation
Replies: 8
Views: 224

### Re: Car Example in Class with De Brogile Equation

Do you guys recall how small he said that the objects would no longer have frequency?
Sun Oct 14, 2018 10:58 am
Forum: Ideal Gases
Replies: 147
Views: 104699

Does anyone know the reading schedule? I have no idea where to look for it so I've just been reading whole chapters on the topics we have been discussing in class.
Sun Oct 14, 2018 10:55 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 198
Views: 140479

### Re: Rusty on High School Chem[ENDORSED]

I am so glad that someone posted this because I always feel like I am out of the loop. There is a lot of people that automatically know the answers for everything and I am so lost sometimes.
Thu Oct 04, 2018 2:31 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 80
Views: 3813

### Re: How does grading for discussion posts work?

Arlene Linares 3A wrote:
Raquel Rodriguez wrote:Do you guys know when our first test is?

In the website, there is a tab that says "Test and Exam Schedule" but the first test will be on October 9 in your discussion section.

^Does anyone know if there is going to be a review for the test?
Thu Oct 04, 2018 2:28 pm
Forum: Administrative Questions and Class Announcements
Topic: 'extra credit' in Sapling Learning
Replies: 7
Views: 679

### Re: 'extra credit' in Sapling Learning

Did anyone figure out if it was extra credit or not?
Thu Oct 04, 2018 2:26 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 217
Views: 115290

### Re: Advice from a Medical Student[ENDORSED]

Thank you so much for your advice, as a pre-med student who is starting to feel the toll of school this is much appreciated. Good luck on your future studies and success!