## Search found 60 matches

Sun Jan 17, 2021 11:23 pm
Forum: Student Social/Study Group
Replies: 25
Views: 63

Practicing with the textbook problems and going to the zoom resources are good places to start.
Sun Jan 17, 2021 11:19 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q > K, Q< K
Replies: 25
Views: 75

### Re: Q > K, Q< K

Q>K means the reaction will move towards the products. Q<K means the reaction will shift toward the products.
Sun Jan 17, 2021 11:16 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: q vs k
Replies: 62
Views: 162

### Re: q vs k

Q moves towards K and when they equal the same thing, the reaction is at equilibrium.
Sun Jan 17, 2021 11:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units to know
Replies: 11
Views: 24

### Re: Units to know

Atm and Torr are both units for pressure that you should know.
Sun Jan 17, 2021 11:13 pm
Forum: Ideal Gases
Topic: R Value
Replies: 17
Views: 36

### Re: R Value

8.206 x 10^-2 is pretty standard for the R but it should always be given.
Sun Jan 10, 2021 7:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q and K
Replies: 8
Views: 24

### Re: Q and K

Q is used at any point in time and is not always at equilibrium. K is strictly for when the reaction is at equilibrium. By comparing Q and K (Q>K or Q<K) you can tell where the reaction is at any point in time and which direction it will move towards in order to reach equilibrium.
Sun Jan 10, 2021 7:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: change in K
Replies: 22
Views: 65

### Re: change in K

K is unaffected by any change except for changes in Temp.
Sun Jan 10, 2021 7:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homogeneous and Heterogeneous Equilibrium
Replies: 13
Views: 58

### Re: Homogeneous and Heterogeneous Equilibrium

To determine if the reaction is homogenous or heterogenous, you should look at all of the compounds present in the reaction including those that won't be included in the calculations for K or Q.
Sun Jan 10, 2021 7:44 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Clarification of terminology
Replies: 15
Views: 89

### Re: Clarification of terminology

Yes, all three express the same idea.
Its more preferable to say that equilibrium "lies" or "sits" on a side instead of "shifts" because equilibrium won't actually move and its position is entirely based on comparison to other Equilibrium constants.
Sun Jan 10, 2021 7:39 pm
Forum: Ideal Gases
Topic: PV=nRT
Replies: 72
Views: 443

### Re: PV=nRT

Pressure * Volume=n(Moles) * R(Gas Constant 8.314 J/mol·K) * Temperature(Kelvin)
Sun Dec 13, 2020 2:34 am
Forum: Identifying Acidic & Basic Salts
Topic: Neutral Salts
Replies: 7
Views: 55

### Re: Neutral Salts

As long as the anion is from a strong acid, and the cation is from a strong base, the salt will be neutral.
Sun Dec 13, 2020 2:25 am
Forum: Naming
Topic: Cobalt vs Cobaltate
Replies: 12
Views: 75

### Re: Cobalt vs Cobaltate

The negative charge at the end of the compound is referenced by adding the -ate suffix at the end of the transition metal.
Sun Dec 13, 2020 2:22 am
Forum: Air Pollution & Acid Rain
Topic: Why does acid rain exist
Replies: 13
Views: 147

### Re: Why does acid rain exist

C02, which is always present in air and continuously being committed by countless sources, is an acid that can lower the pH of rain and cause acid rain. Other molecules that find their way into the atmosphere, like SO2 from the combustion of coal, has the same effect to even greater extents.
Sun Dec 13, 2020 2:19 am
Forum: Bronsted Acids & Bases
Topic: Strong bases oxides vs hydroxides
Replies: 4
Views: 58

### Re: Strong bases oxides vs hydroxides

I believe that metal hydroxides are the stronger of the two simply because they are listed in any list of strong bases while metal oxides are never present. The textbook list says to assume that the base is weak if it isn't included on the list so I wouldn't stray from that rule.
Sun Dec 13, 2020 2:10 am
Forum: Amphoteric Compounds
Topic: Recognizing Amphoteric Substances
Replies: 8
Views: 67

### Re: Recognizing Amphoteric Substances

Amphoteric substances need to be able to accept and donate protons. A negative charge is a good indicator that a Hydrogen can be accepted, but if the molecule already has a hydrogen then the molecule can also donate a proton. This isn't a rule for all amphoteric substances but it can be helpful.
Sun Dec 06, 2020 10:30 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Differences in Rotation between σ-Bonds and π-Bonds
Replies: 5
Views: 58

### Re: Differences in Rotation between σ-Bonds and π-Bonds

From what I've read, you are right in thinking that rotation would cause the pi bonds to break. This is because the pi bonds depend on the parallel orientation of the p orbitals and any rotation would result in the orbitals no longer being parallel.
Sun Dec 06, 2020 10:24 pm
Forum: Significant Figures
Topic: When should I start looking at sig figs?
Replies: 31
Views: 234

### Re: When should I start looking at sig figs?

Graphing calculators are my saving grace here, I just save all rounding until the very end.
Sun Dec 06, 2020 10:13 pm
Forum: Student Social/Study Group
Topic: Evaluations
Replies: 17
Views: 91

### Re: Evaluations

I've seen a lot of wishful thinking about extra credit for this class but haven't heard about any in previous quarters so I kinda doubt there will be any.
Sun Dec 06, 2020 10:10 pm
Forum: Administrative Questions and Class Announcements
Topic: CCLE Lectures
Replies: 9
Views: 62

### Re: CCLE Lectures

I was trying a few hours ago and the video playback on ccle froze midway through a lecture on my laptop. I switched to a desktop and I almost finished the lecture but it froze and stopped working right at the end. Now I can't access lectures on either. Kinda frustrating that it's been like this for ...
Sun Dec 06, 2020 10:05 pm
Forum: Lewis Acids & Bases
Topic: lewis vs bronsted
Replies: 10
Views: 63

### Re: lewis vs bronsted

Lewis acids and bases focus on the movement of electrons, while bronsted looks at the movement of protons.
Sun Nov 29, 2020 10:49 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis structure
Replies: 10
Views: 94

### Re: Lewis structure

Always keep a periodic table handy. The distance between atoms on the table is the best way to determine differences in electronegativity which helps determine the bond type.
Sun Nov 29, 2020 10:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: sapling 17 & 18
Replies: 6
Views: 53

### Re: sapling 17 & 18

For organic molecules like in #18, the chemical formulas are written to help you know the location of each atom. For problems like #17 just try to fill the octet of each atom and try using double bonds to help.
Sun Nov 29, 2020 10:43 pm
Forum: Electronegativity
Topic: Be vs Cl
Replies: 13
Views: 108

### Re: Be vs Cl

As a general rule, you can determine which is more electronegative based on the atoms' proximity to the top right corner. In this case, Cl is much closer to the top right and is much more electronegative.
Sun Nov 29, 2020 10:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 11
Views: 192

### Re: Bond Order

When the bond order is zero, the molecule is too unstable and won't continue to exist.
Sun Nov 29, 2020 10:36 pm
Forum: Bond Lengths & Energies
Topic: Boiling/Melting Point
Replies: 20
Views: 142

### Re: Boiling/Melting Point

Intermolecular forces like london dispersion and hydrogen bonding play a big role in boiling and melting points.
Sun Nov 22, 2020 10:38 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 19
Views: 150

### Re: Ionization Energy

The outermost electrons will be the first to go as they are furthest away from the nucleus and experience electron shielding which makes them easier to be separated.
Sun Nov 22, 2020 10:21 pm
Forum: Bond Lengths & Energies
Topic: Boiling/Melting Point
Replies: 20
Views: 142

### Re: Boiling/Melting Point

Intermolecular forces such as London forces and hydrogen bonding will require more energy to break bonds and allow boiling to occur.
Sun Nov 22, 2020 9:25 pm
Forum: Trends in The Periodic Table
Topic: Ionic Character
Replies: 11
Views: 92

### Re: Ionic Character

The difference in electronegativity. If the difference is >2, it is ionic, and if it is <1.5 the bond is covalent.
Sun Nov 22, 2020 9:19 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: London Dispersion
Replies: 33
Views: 159

### Re: London Dispersion

London forces are always occurring but they aren't as significant on smaller molecules, especially when compared to other intermolecular forces.
Sun Nov 22, 2020 9:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polarity from lewis structure
Replies: 7
Views: 28

### Re: polarity from lewis structure

Because of the linear structure, the dipoles cancel out and it is nonpolar.
Sun Nov 15, 2020 11:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Structure plausibility
Replies: 5
Views: 34

### Re: Structure plausibility

The most stable structure will be the one with the least formal charges, but the location of those charges is also important. It is more stable for the negative formal charges to be on the more electronegative atoms and positive formal charges on the less electronegative atoms. Sapling #5 is a good ...
Sun Nov 15, 2020 11:26 pm
Forum: Dipole Moments
Topic: London Dispersion forces
Replies: 14
Views: 75

### Re: London Dispersion forces

All molecules experience London Dispersion forces. The sapling problem was probably asking you to choose the most apparent force present.
Sun Nov 15, 2020 11:16 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidations Numbers
Replies: 4
Views: 50

### Re: Oxidations Numbers

Thanks for the resources and explanations. I was really confused with oxidation #'s.
Sun Nov 15, 2020 11:12 pm
Forum: Dipole Moments
Topic: London Dispersion Forces
Replies: 4
Views: 15

### Re: London Dispersion Forces

Dispersion forces are present between all molecules. The strength of those forces increases with the size of the molecules involved.
Sun Nov 15, 2020 11:09 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2
Replies: 23
Views: 133

### Re: Midterm 2

The midterm is still during our discussion sections so it's the same amount of time.
Sun Nov 08, 2020 8:58 pm
Forum: Ionic & Covalent Bonds
Topic: Oxidation number
Replies: 7
Views: 43

### Re: Oxidation number

Thanks for all the resources! This helped a lot!
Sun Nov 08, 2020 8:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2 Question Count
Replies: 17
Views: 106

### Re: Midterm 2 Question Count

I'm not sure about the number of questions, but I think it's safe to assume that it will be worth the same amount of points and that the format (respondus) will be the same as well.
Sun Nov 08, 2020 8:42 pm
Forum: Trends in The Periodic Table
Topic: # of electrons
Replies: 23
Views: 118

### Re: # of electrons

Assuming the atom is neutral, the # of electrons will = the number of protons (given by the atomic number).
Sun Nov 08, 2020 8:38 pm
Forum: Trends in The Periodic Table
Topic: Tips for learning the trends in the Periodic table
Replies: 11
Views: 69

### Re: Tips for learning the trends in the Periodic table

Charts like these are a great visual to help learn the trends but you should definitely try to back the visuals up with an understanding of the concepts.
Sun Nov 08, 2020 8:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Taking Bio and Chem simultaneously
Replies: 26
Views: 114

### Re: Taking Bio and Chem simultaneously

The advice I got from premeds from earlier years was to choose bio or chem to do first along with math and then take the other science after. I guess taking both at the same time is doable, but I don't have the study habits to sustain that level of work so I'm taking bio after I finish chem.
Sun Nov 01, 2020 11:26 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing SI Units
Replies: 14
Views: 110

### Re: Memorizing SI Units

I think you definitely want to have a good idea of the SI units but the weirder conversions are usually on the formula sheet unless we are told otherwise.
Sun Nov 01, 2020 11:21 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8517
Views: 1470803

### Re: Post All Chemistry Jokes Here

How are Copper and Zinc related?

They're CuZn's
Sun Nov 01, 2020 11:16 pm
Forum: DeBroglie Equation
Replies: 21
Views: 129

Avogadro's' number is the constant number of any type of particle in a mole. For example, when you are given the molar mass of Hydrogen, that is the weight of 6.022x10^23 hydrogen atoms.
Sun Nov 01, 2020 11:10 pm
Forum: Student Social/Study Group
Topic: Halloween!!!
Replies: 54
Views: 332

### Re: Halloween!!!

I watched a movie with my family! It wasn't horror though lol.
Sun Nov 01, 2020 11:02 pm
Forum: Student Social/Study Group
Topic: Test Scored for Midterm 1
Replies: 49
Views: 382

### Re: Test Scored for Midterm 1

I believe my TA mentioned them being graded by this Friday.
Sun Oct 25, 2020 11:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Replies: 92
Views: 2081

I recently went to my first workshop and it was super helpful. Also, the modules are really useful if you want to zero in on a specific concept that you are unsure about.
Sun Oct 25, 2020 11:35 pm
Forum: Student Social/Study Group
Topic: Midterm Materials
Replies: 2
Views: 20

### Re: Midterm Materials

In some of Dr. Lavelle's emails, he sends pdf's titled "Constants and Equations" and "Periodic Table" for us to print out so you should definitely find those and have them ready. Also, my TA said that any calculator should be fine.
Sun Oct 25, 2020 11:30 pm
Forum: General Science Questions
Topic: Webcams for Midterm
Replies: 6
Views: 31

### Re: Webcams for Midterm

I found this in a post from Dr. Lavelle: "For midterms and final, joining the Zoom proctoring session using your cell phone is another option. The student needs to make sure they have Zoom set up on their phone with their UCLA account, and the link to the Zoom session. Using your phone seems mo...
Sun Oct 25, 2020 11:08 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Module #18
Replies: 5
Views: 52

### Re: Module #18

I think because the uncertainty is given in terms of the radius it's best to stick with the given values and not solve in terms of the diameter. It might be solvable either way but it seems like it's an unneeded step.
Sun Oct 25, 2020 8:46 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Module #18
Replies: 5
Views: 52

### Re: Module #18

Did they just omit the 1 in 1x10^8 then? I guess that's equivalent but it definitely threw me off.
Sun Oct 18, 2020 11:20 pm
Forum: Photoelectric Effect
Topic: Sapling clarification
Replies: 15
Views: 100

### Re: Sapling clarification

Are these sapling problems similar to what we might see on the midterm? Or should I focus more on the textbook problems in that regard?
Sun Oct 18, 2020 11:17 pm
Forum: Student Social/Study Group
Topic: Step Up Sessions
Replies: 9
Views: 82

### Re: Step Up Sessions

I'm starting to notice that I need a lot more extra practice so I'll check these sessions out. Thanks!
Sun Oct 18, 2020 10:55 pm
Forum: Einstein Equation
Topic: Einstein Equation
Replies: 10
Views: 223

### Re: Einstein Equation

The ν used for frequency is the greek letter "nu" which looks almost identical to a v. I think for the most part problems should be pretty clear on what is being asked for, such as when a wavelength is given.
Sun Oct 18, 2020 10:41 pm
Forum: Photoelectric Effect
Topic: Sapling clarification
Replies: 15
Views: 100

### Re: Sapling clarification

Sun Oct 18, 2020 10:32 pm
Forum: Student Social/Study Group
Topic: How are you studying?
Replies: 203
Views: 1291

### Re: How are you studying?

This whole thread is super helpful, thanks for all the tips! Still trying to adjust to college classes lol.
Sun Oct 11, 2020 8:45 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling HW Number 7
Replies: 12
Views: 129

### Re: Sapling HW Number 7

Hello everyone i was wondering if anyone could help me with molarity because i never really captured it and i feel like im behind on it. Also if anyone whos where to find actual tutors please let me know. Molarity is the molar concentration of a compound, the formula being M=n/v with the variables ...
Sun Oct 11, 2020 8:33 pm
Forum: SI Units, Unit Conversions
Topic: Textbook
Replies: 22
Views: 181

### Re: Textbook

I can get to the homework problems through CCLE but how do I get to the textbook with the free trial? If you can get onto sapling, the textbook should be available on the far right side when you are on the main class page with the big bold "University of California, Los Angeles - CHEM 14A - Fa...
Sun Oct 11, 2020 8:29 pm
Forum: SI Units, Unit Conversions
Topic: Showing Work
Replies: 8
Views: 51

### Re: Showing Work

AP Chem provided partial credit for work that shows the correct concepts and formulas being applied even if answers don't end up being correct. I'm assuming the same thing will happen in the midterms and final to some extent.
Sun Oct 11, 2020 8:23 pm
Forum: Limiting Reactant Calculations
Topic: How do we find the amount of oxygen in combustion?
Replies: 10
Views: 525

### Re: How do we find the amount of oxygen in combustion?

Why does combustion always result in H2O and CO2 and not other compounds? From what I understand, in an ideal combustion reaction H20 and CO2 are the only products. An example of different compounds being released is in an incomplete combustion reaction (which occurs due to a poor supply of O2) whe...
Sun Oct 11, 2020 8:07 pm
Forum: Limiting Reactant Calculations
Topic: Sapling HW 10
Replies: 9
Views: 127

### Re: Sapling HW 10

You can use the molecular formulas to find the molar mass, but I just searched it up and got molar mass of butanone on the internet. You would only need to know the formulas for the 2-butanone and 3-methyl-3-hexanol since the other product is in excess. To approach the problem, first use the densit...