Search found 55 matches

by Areli C 1L
Thu Jan 16, 2020 7:12 am
Forum: Ideal Gases
Topic: Topics for Test 1
Replies: 14
Views: 59

Re: Topics for Test 1

805097738 wrote:The UA's said the material would cover up to this friday's class material so I would focus of the first two weeks of information. The lecture videos that Lavelle posted cover a lot of the information and have great practice problems!

I forgot about his lecture videos! Nice :)
by Areli C 1L
Thu Jan 16, 2020 7:11 am
Forum: Ideal Gases
Topic: Topics for Test 1
Replies: 14
Views: 59

Re: Topics for Test 1

I'm not sure if Lavelle would structure his exams as he did 14A, but his tests were wickedly based on the homework. So, if you understand every single homework problem (Even the long complex ones) you will do awesome) :)
by Areli C 1L
Thu Jan 16, 2020 7:07 am
Forum: Ideal Gases
Topic: R constant
Replies: 6
Views: 22

Re: R constant

Qiu Ya Wu 4I wrote:Lavelle gives you 4 different values for the R constant on his formula sheet during tests. Whichever one you use depends on the units given in the problem.

Do you know if the problems will mention directly which R constant to use?(Like a given)
by Areli C 1L
Thu Jan 16, 2020 7:05 am
Forum: Ideal Gases
Topic: bars vs atm
Replies: 8
Views: 26

Re: bars vs atm

The units will be different and I don't think Lavelle will not mention the type of pressure (bar or atm) used in the problem. Either way, just be sure to maintain the units so you don't get points deducted.
by Areli C 1L
Thu Jan 16, 2020 7:01 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Factors
Replies: 7
Views: 24

Re: Factors

Yes, if I'm not mistaken, I think Lavelle did mention that temp would be the only factor that changes the K eq.
by Areli C 1L
Wed Jan 08, 2020 6:10 pm
Forum: Ideal Gases
Topic: R constant in PV=nRT
Replies: 9
Views: 35

Re: R constant in PV=nRT

Most likely it will be R=8.314 J/(K*mol) as it will be cancelled out with T= Kelvin. Also it probably will be given in our constant sheet on exam days.
by Areli C 1L
Wed Jan 08, 2020 6:07 pm
Forum: Ideal Gases
Topic: Review Ideal Gases
Replies: 6
Views: 50

Re: Review Ideal Gases

Organic Chemistry Tutor! Great Youtube channel for chemistry help :)
by Areli C 1L
Wed Jan 08, 2020 5:59 pm
Forum: Ideal Gases
Topic: Gas Law
Replies: 6
Views: 29

Re: Gas Law

I believe Prof. Lavelle mentioned it in class today. The gas law allows you to relate Pressure and Volume to concentration. You are then able to convert between partial pressures and concentration of a reactant in a reaction. [Conc.]=P/(RT)
by Areli C 1L
Wed Jan 08, 2020 5:53 pm
Forum: Ideal Gases
Topic: K and Q
Replies: 13
Views: 48

Re: K and Q

From an earlier post, I learned that K is for a reaction that is at equilibria or the equilibrium constant. Q is calculated to determine where the reaction will proceed, Forward or Reverse since the rxn is not at equilibrium.
by Areli C 1L
Wed Jan 08, 2020 5:51 pm
Forum: Ideal Gases
Topic: Q and K
Replies: 7
Views: 38

Re: Q and K

K describes the reaction once it reaches equilibrium. Q is calculated the same way as K, but it is for the reaction at any point in time that is not equilibrium. You can find Q and compare it with K to determine which way the reaction will proceed. Hope this helps. This makes so much sense! Thank y...
by Areli C 1L
Fri Dec 06, 2019 11:13 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7742
Views: 1060753

Re: Post All Chemistry Jokes Here

Why do chemists enjoy working with ammonia?
-Because it's pretty basic stuff.
by Areli C 1L
Fri Nov 22, 2019 9:15 am
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 Atoms
Replies: 6
Views: 34

Re: Hydrogen Bonding Atoms

I believe it does not matter whether they are bonded or not. Since its an intermolecular interaction H bond will be able to pair with any NOF atom.
by Areli C 1L
Fri Nov 22, 2019 9:13 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.5
Replies: 5
Views: 23

Re: 2E.5

It depends on the amount of lone pairs the central atoms has. This chart was helpful for me when trying to memorize them. Hopefully it appears. https://www.studocu.com/en-us/document/george-mason-university/physical-chemistry-lab-ii/summaries/vsepr-summary/3958564/view
by Areli C 1L
Thu Nov 21, 2019 4:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 14
Views: 109

Re: Test 2

Kristina Rizo 3K wrote:I know the bonds (sigma and pi), molecular shapes, bond angles and the intermolecular forces will be on test 2. I'm not sure if that is all though.

Do you know if we will be expected to memorize the bond angles?
I thought he mentioned in lecture that we weren't but maybe I didn't listen correctly.
by Areli C 1L
Thu Nov 21, 2019 3:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 14
Views: 109

Test 2

Can someone provide some important concepts to keep in mind for test 2? I have the memory of a goldfish and I really want to do well on this test. Thank you!
by Areli C 1L
Thu Nov 21, 2019 3:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: test 2
Replies: 3
Views: 39

Re: test 2

Megan Ngai- 3B wrote:^ retweet

re-retweet
by Areli C 1L
Thu Nov 21, 2019 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 7
Views: 88

Re: Test 2

I think you can just say "bent" no matter if it is AX2E or AX2E2, but if asked to specify the electron geometry, you should state that it is trigonal planar for AX2E and tetrahedral for AX2E2. Hope this answer helps! Do you think we can specify all the names (Trigonal planar and tetrahedr...
by Areli C 1L
Thu Nov 21, 2019 3:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Name confusion
Replies: 4
Views: 31

Re: Name confusion

Like those above me mentioned, it all depends on the amount of lone pairs and bonded pairs to the atom. Tetrahedral doesn't have any lone pairs, whereas the see-saw molecular shape does. :)
by Areli C 1L
Sun Nov 17, 2019 7:46 pm
Forum: Ionic & Covalent Bonds
Topic: Electronegativity
Replies: 7
Views: 41

Re: Electronegativity

In case we aren't given it, it is best to know the trends from the periodic table. As we are given the Periodic table, just draw the trends directly on there for easy access.
by Areli C 1L
Sun Nov 17, 2019 7:38 pm
Forum: Ionic & Covalent Bonds
Topic: Strength and Length
Replies: 18
Views: 105

Re: Strength and Length

Longer Bond=Weaker bond
Shorter Bond= Stronger bond
:)
by Areli C 1L
Sun Nov 17, 2019 7:34 pm
Forum: Ionic & Covalent Bonds
Topic: Dipole-Dipole Interactions
Replies: 3
Views: 22

Re: Dipole-Dipole Interactions

April Meza 3K wrote:Here is an example of a dipole-dipole moment.


Thank you for providing a Visual. :) It is very helpful
by Areli C 1L
Sun Nov 17, 2019 7:34 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bonds
Replies: 6
Views: 30

Re: Hydrogen Bonds

So only 3 elements can partake in hydrogen bonding: Oxygen, Nitrogen, and Flourine.
by Areli C 1L
Sun Nov 17, 2019 7:31 pm
Forum: Ionic & Covalent Bonds
Topic: London Dispersion
Replies: 13
Views: 78

Re: London Dispersion

Ah this one is the easiest :) From my understanding, all molecules will have London dispersion as an intermolecular force.
by Areli C 1L
Mon Nov 11, 2019 6:00 am
Forum: Bond Lengths & Energies
Topic: Size
Replies: 9
Views: 42

Re: Size

Does bond length also affect how strong the bond is? As Serena Siddiq said "The larger the radius of the atoms, the farther each of their centers are apart, and therefore, [they have a longer and weaker bond length than smaller radius atoms]. The smaller the radius of the atoms, the closer the...
by Areli C 1L
Mon Nov 11, 2019 5:56 am
Forum: Dipole Moments
Topic: Hydrogen bonds
Replies: 17
Views: 87

Re: Hydrogen bonds

From my understanding just those 3
by Areli C 1L
Tue Nov 05, 2019 6:36 pm
Forum: Properties of Light
Topic: Midterm formulas
Replies: 6
Views: 73

Re: Midterm formulas

yes ma'am :)
by Areli C 1L
Tue Nov 05, 2019 4:54 pm
Forum: DeBroglie Equation
Topic: Midterm Practice 4B
Replies: 2
Views: 44

Re: Midterm Practice 4B

So first you have to use De Broglie's equation to solve for velocity since you can't just use the speed of light equation because the wavelength given is for an electron and not light. Then you would just use the photoelectric effect equation and plug in the values for work function and kinetic ene...
by Areli C 1L
Tue Nov 05, 2019 2:20 pm
Forum: DeBroglie Equation
Topic: Midterm Practice 4B
Replies: 2
Views: 44

Midterm Practice 4B

8. b) A newly designed laser pointer with a certain frequency is pointed at a sodium metal surface. An electron is ejected from the metal surface with wavelength of 1.10 nm. What is the frequency of the light from the laser pointer? The work function of sodium is 150.6 kJ∙mol-1. I am getting lost on...
by Areli C 1L
Sun Nov 03, 2019 7:43 pm
Forum: Electronegativity
Topic: electronegativity trend
Replies: 9
Views: 35

Re: electronegativity trend

The larger the shell gets the lower electronegativity the element will have because that larger outer shell's electron is a lot farther from the nucleus.
by Areli C 1L
Sun Nov 03, 2019 7:39 pm
Forum: Electronegativity
Topic: Identifying the central atom
Replies: 3
Views: 21

Re: Identifying the central atom

Yuri Lin 4H wrote:I think the rule of thumb is that the central atom is the least electronegative atom, not the one with the lowest ionization energy, though I might be wrong. Nitrogen has a lower electronegativity than oxygen, so it would be the central atom.


Thank you! I too was puzzled.
by Areli C 1L
Sun Nov 03, 2019 7:26 pm
Forum: Octet Exceptions
Topic: Radical
Replies: 6
Views: 37

Re: Radical

Basically they are highly reactive because they are desperately trying to gain a complete octet, so theyd try to grab it from anywhere.
by Areli C 1L
Sun Nov 03, 2019 7:24 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 5
Views: 33

Re: Drawing Lewis Structures

When you draw a lewis structure you have to pay special attention to the valence electrons in each atom; they help determine if there are single/double/triple bonds. There is normally a center atom, and that is normally the atom that has the lowest ionization energy. For bonds (when the molecule is...
by Areli C 1L
Sun Nov 03, 2019 7:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Bruincast
Replies: 4
Views: 47

Re: Bruincast

I've also looked into that but came back empty. :( As the others have said we only have the Video modules that show us past lectures of very similar (if not the same) problems from class itself.
by Areli C 1L
Sun Oct 27, 2019 8:27 pm
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 132
Views: 76583

Re: Reading the textbook [ENDORSED]

I've definitely have been in your shoes before. If the reading feels a intimidating, you should watch some youtube videos first about the concept so you won't go in blind. After that, as you go back to the reading it will feel more familiar and less intimidating!
by Areli C 1L
Sun Oct 27, 2019 8:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 153
Views: 85501

Re: Advice from a Medical Student [ENDORSED]

Thank you so much! This was quite insightful
by Areli C 1L
Sun Oct 27, 2019 2:54 pm
Forum: Lewis Structures
Topic: Drawing the structure
Replies: 7
Views: 48

Re: Drawing the structure

Just be sure to know which elements are able to expand their octet so it doesn't mess up your lewis structure or cause confusion.
by Areli C 1L
Sun Oct 27, 2019 2:50 pm
Forum: Lewis Structures
Topic: Anion/Cations
Replies: 2
Views: 25

Re: Anion/Cations

Adding on to what the post above me said, I believe Usually it is denoted by brackets and then the charge is placed at the top right corner. If it has a 2+ charge then its be a cation and vice versa.
by Areli C 1L
Sun Oct 20, 2019 8:45 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 154

Re: Speed of Light

Yes, it is a constant. Some prefer to write it as 3.00x10^8 or 2.998x10^8 believe it or not sometimes, depending on which one you use, it can change your answer slightly. So for accuracy try to use the 2.998x10^8. Then your final answer should be in the appropriate Sig figs :)
by Areli C 1L
Sun Oct 20, 2019 8:40 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 95
Views: 19688

Re: Final Jitters

I try to prepare myself as much as possible, and try to get some sleep! Sleep is super important, or try to get little naps here and there so you don't feel like you're lacking.
(lord knows anxiety is a sleep killer).
by Areli C 1L
Sun Oct 20, 2019 8:34 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2722

Re: Test 1 [ENDORSED]

I can't find my test grades on ccle, where do I go? I had the same problem, you should try to check your discussion section or go talk to your discussion TA if that doesn't work. I thought TA's were supposed to give our tests back, but the score itself isn't necessarily the grade we got because of ...
by Areli C 1L
Wed Oct 16, 2019 12:31 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question regarding definition of molecules
Replies: 5
Views: 57

Re: Question regarding definition of molecules

From my understanding, Avogadro's Number can be used to find Atoms, Molecules and Formula units of a compound. :)
by Areli C 1L
Wed Oct 16, 2019 12:28 pm
Forum: SI Units, Unit Conversions
Topic: Chemistry Grades
Replies: 4
Views: 33

Re: Chemistry Grades

As everyone else had mentioned, my TA also has only inputted homework assignments so far. Hopefully soon though!
by Areli C 1L
Fri Oct 11, 2019 9:58 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7742
Views: 1060753

Re: Chemistry Jokes

If H20 is water, what is H204? Drinking, bathing, washing, swimming, etc. If H2O is the formula for water, what is the formula for ice? H2O cubed. Anyone know any jokes about the element sodium? Na. Have been trying to figure out the first joke for almost a year and I can't figure out lmao Hahah it...
by Areli C 1L
Fri Oct 11, 2019 9:53 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7742
Views: 1060753

Re: Chemistry Jokes

Shreyesi Srivastava 2D wrote:Do you have 11 protons?
Cause you sodium fine

How have I never heard this one! HAHAh! :')
by Areli C 1L
Fri Oct 11, 2019 9:46 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Wrong Textbook
Replies: 12
Views: 163

Re: Wrong Textbook

I have the 7th edition PDF if you want to use that one. I know some prefer the physical book, but that's expensive. Send me a Pm if you're interested, I'll gladly share it :)
by Areli C 1L
Fri Oct 11, 2019 9:27 am
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 20
Views: 204

Re: Balancing Chemical Reactions

Jarrett Peyrefitte 1L wrote:Try to make a list of reactants and products with their respective number of molecules and balance it one by one.

Yes! This simple list helps with confusion and knowing how much of what is on each side. I highly recommend this. :)
by Areli C 1L
Fri Oct 11, 2019 9:23 am
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 228
Views: 103391

Re: Saying Thank You to Dr. Lavelle

Speaking as someone who has taken 14A before and didn't do so well, Dr. Lavelle you really make these concepts so interesting and easy to understand. Your passion seeps through every lecture making your students feel as passionate to learn as you are to teach! Truly a one-of-a-kind professor :)
by Areli C 1L
Fri Oct 11, 2019 9:19 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 153
Views: 85501

Re: Advice from a Medical Student [ENDORSED]

Wow, this is very helpful. Thank you :)
by Areli C 1L
Fri Oct 11, 2019 9:17 am
Forum: Limiting Reactant Calculations
Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Replies: 68
Views: 1566

Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]

I think it would be best to show your work how you learned it rather than confusing yourself by adding minor steps. However, the minor steps might help you receive partial credit if your answer is incorrect. :)
by Areli C 1L
Thu Oct 03, 2019 7:23 pm
Forum: Balancing Chemical Reactions
Topic: Understanding how to get whole #s [ENDORSED]
Replies: 18
Views: 155

Re: Understanding how to get whole #s [ENDORSED]

From what I've been reading on the forums, our final answer should always be in the correct number of significant figures in order to be concise. So if the fewest number of sig figs in the problem was 4 then your final answer should contain only 4 sig figs.
by Areli C 1L
Thu Oct 03, 2019 7:19 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 6
Views: 82

Re: Sig Figs

Can we round to the least amount of sig figs that are allowed for each step in our calculation? So basically round at each calculation to 2,3 sig figs?
by Areli C 1L
Thu Oct 03, 2019 7:13 pm
Forum: SI Units, Unit Conversions
Topic: Formula Names
Replies: 7
Views: 61

Re: Formula Names

I would agree with everyone else, prefixes and suffixes are important to remember as it will also help you write out formula names given only the chemical formula. I'm pretty sure they'll give us a list of chemicals they'd want us to remember for the exam and maybe try to write the names of others i...
by Areli C 1L
Thu Oct 03, 2019 7:01 pm
Forum: SI Units, Unit Conversions
Topic: mol, g.mol and g.mol-1
Replies: 12
Views: 148

Re: mol, g.mol and g.mol-1

From what I've seen so far, grams/mole is equal to g.mol-1. Lavelle prefers us to write it as the latter since it makes canceling units simpler. I haven't seen g.mols though, so I wouldn't be able to explain the difference.

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