Search found 102 matches
- Thu Mar 11, 2021 6:40 pm
- Forum: Student Social/Study Group
- Topic: STEM Clubs!
- Replies: 7
- Views: 569
Re: STEM Clubs!
neuroscience undergrad is a good one! don't have to be a neuroscience major, it's really fun and informative overall! Recommend
- Thu Mar 11, 2021 6:21 pm
- Forum: Student Social/Study Group
- Topic: chem community points
- Replies: 23
- Views: 1038
Re: chem community points
We should have 50 points by Sunday, he might give us more time after the final to post.
- Thu Mar 11, 2021 6:20 pm
- Forum: Student Social/Study Group
- Topic: How are y'all doing?
- Replies: 46
- Views: 2157
Re: How are y'all doing?
It's been tough. Life has been hard, but nothing I can't handle. Hopefully.
- Thu Mar 11, 2021 6:18 pm
- Forum: First Order Reactions
- Topic: Half Life Unit
- Replies: 38
- Views: 1332
Re: Half Life Unit
Half life is usually calculated in seconds, but if the question gives you a certain unit, you should probably stick to that.
- Thu Mar 11, 2021 6:16 pm
- Forum: Zero Order Reactions
- Topic: When to use each order
- Replies: 19
- Views: 1005
Re: When to use each order
In order to determine which order, you can sum up the exponents in the rate law. However, i find the graphs to be more useful, so I really appreciate whoever posted that!
- Thu Mar 11, 2021 6:14 pm
- Forum: General Rate Laws
- Topic: Wk 9/10 Sapling #13
- Replies: 8
- Views: 396
Re: Wk 9/10 Sapling #13
Important to note that NOT all of the elements in the answer bank will be used!
- Wed Mar 03, 2021 3:16 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Order of reaction
- Replies: 16
- Views: 1061
Re: Order of reaction
The order of reaction refers to the power dependence of the rate on the concentration of each reactant. For a first-order reaction, the rate is dependent on the concentration of a single species. The overall order of the reaction is found by adding up the individual orders.
- Wed Mar 03, 2021 3:11 pm
- Forum: Student Social/Study Group
- Topic: Playlist
- Replies: 86
- Views: 6090
Re: Playlist
Been listening to a lot of throwback music, especially 2000s R&B. You can never go wrong with that. But when I study, I like to put on classical music to really focus.
- Wed Mar 03, 2021 3:10 pm
- Forum: Student Social/Study Group
- Topic: Textbook Problem Strategies
- Replies: 17
- Views: 693
Re: Textbook Problem Strategies
I usually like to do the problems w/ concepts that I found most challenging in class. Therefore, I could focus on those more and try to understand why I'm having trouble. I like to redo them before exams so they are fresh in my memory, but only on ones that I know will most likely be on the exams. T...
- Wed Mar 03, 2021 3:04 pm
- Forum: Student Social/Study Group
- Topic: What organizations are you guys in?
- Replies: 53
- Views: 2860
Re: What organizations are you guys in?
I'm part of the Neuroscience Undergrad Club, but I plan on joining more soon.
- Wed Mar 03, 2021 3:03 pm
- Forum: Student Social/Study Group
- Topic: Fave movie/show
- Replies: 67
- Views: 4141
Re: Fave movie/show
Knives out is a great movie! 11/10 recommend.
- Thu Feb 25, 2021 6:35 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling W7/8 Q. 5
- Replies: 18
- Views: 1004
Re: Sapling W7/8 Q. 5
I'm also having trouble with this problem. I'm not sure what I'm doing wrong.. For the balanced equation, I get ClO- + [Pb(OH)4]2- ---> Cl- + 2OH- + 2PbO2 + H2O
- Thu Feb 25, 2021 6:27 pm
- Forum: Administrative Questions and Class Announcements
- Topic: When is Sapling HW due?
- Replies: 22
- Views: 846
Re: When is Sapling HW due?
Sapling HW is due this upcoming Sunday at midnight, Feb. 28th. Since it covers both week 7 & 8, it was extended a week.
- Thu Feb 25, 2021 6:01 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Sapling Week 7/8 #10
- Replies: 4
- Views: 214
Re: Sapling Week 7/8 #10
The standard reduction potential is the way to go: U should get Au3+, Cu+, Fe2+, Al3+
- Thu Feb 25, 2021 5:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 2 score release
- Replies: 13
- Views: 789
Re: Midterm 2 score release
They were released today! They can be accessed in ccle under grades. Lavelle also sent out an email going over specifics.
- Thu Feb 25, 2021 5:53 pm
- Forum: Balancing Redox Reactions
- Topic: Week 7/8 Sapling #4
- Replies: 3
- Views: 252
Re: Week 7/8 Sapling #4
^You are correct, HCl would be included with Au as (HAuCl4)
- Sun Feb 21, 2021 11:11 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Water and voltage
- Replies: 9
- Views: 1317
Re: Water and voltage
Water does affect the voltage of a cell because it will change the concentration,
- Sun Feb 21, 2021 11:08 am
- Forum: Student Social/Study Group
- Topic: Test curve?
- Replies: 40
- Views: 2663
Re: Test curve?
A handful of people tend to do good in his exams, so curves aren't likely.
- Sun Feb 21, 2021 11:05 am
- Forum: General Science Questions
- Topic: No Lavelle Chem 14C?
- Replies: 68
- Views: 4134
Re: No Lavelle Chem 14C?
Just found out Lavelle won't be teaching 14C.. Will be a hard parting, but grateful for the time.
- Sun Feb 21, 2021 11:04 am
- Forum: Student Social/Study Group
- Topic: Points needed to pass?
- Replies: 76
- Views: 6304
Re: Points needed to pass?
The syllabus states that you need at least a 50% to pass the class with a C-
- Sun Feb 21, 2021 11:02 am
- Forum: Student Social/Study Group
- Topic: We made it through Midterm 2!
- Replies: 71
- Views: 3376
Re: We made it through Midterm 2!
Definitely felt a weight get off my shoulder. Week 8, almost done!
- Sat Feb 13, 2021 1:36 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
- Replies: 26
- Views: 1145
Re: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
The values can be found in the equation sheet. What would be most hopefully is to contextually understand how to use/apply these values when needed.
- Sat Feb 13, 2021 1:30 pm
- Forum: Ideal Gases
- Topic: Units for K
- Replies: 29
- Views: 1052
Re: Units for K
K has no units because since it is a ratio, they cancel out in the end.
- Sat Feb 13, 2021 1:16 pm
- Forum: Student Social/Study Group
- Topic: Thoughts on Upcoming Midterm 2
- Replies: 41
- Views: 1534
Re: Thoughts on Upcoming Midterm 2
The upcoming midterm should be fairly similar to the first one. Same format and everything. Keep doing textbook problems and getting in the habit of solving similar problems to those. Sapling is helpful as well and if there are any further questions, a lot of other resources are available.
- Sat Feb 13, 2021 1:13 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Kelvin conversion
- Replies: 40
- Views: 2643
Re: Kelvin conversion
To convert Celsius to Kelvin, you just have to add 273. The equation sheet has 273.15 to add more precision.
- Sat Feb 13, 2021 1:02 pm
- Forum: Student Social/Study Group
- Topic: Classes for next quarter?
- Replies: 165
- Views: 12161
Re: Classes for next quarter?
Chem 14C is definitely in my planner!
- Sat Feb 06, 2021 12:07 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy reactions
- Replies: 9
- Views: 400
Re: Enthalpy reactions
If the total energy required to break bonds in the reactants is more than the total energy released when new bonds are formed in the products, it is an endothermic reaction
- Sat Feb 06, 2021 12:00 am
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community Grades
- Replies: 4
- Views: 261
Re: Chem Community Grades
I believe our TAs count our points, but they should be fixed by the end of this week. Many others have been having issues with this as well, but you should be fine by the end of the quarter!
- Fri Feb 05, 2021 5:02 pm
- Forum: Student Social/Study Group
- Topic: Sapling HW and exams
- Replies: 19
- Views: 709
Re: Sapling HW and exams
Sapling questions are useful to study, but I prefer the textbook problems because some of them tend to be on the exam, not all the time, but it's still good practice.
- Fri Feb 05, 2021 4:29 pm
- Forum: Student Social/Study Group
- Topic: Studying When You Don't Want to
- Replies: 48
- Views: 2438
Re: Studying When You Don't Want to
Keeping an agenda is really helpful to organize and stay on top of things. Whenever you're in lecture, make notes on subjects that may seem difficult or you just need to go over again. It's especially hard to find the motivation to stay on top of things, so make sure you give yourself some time off ...
- Fri Feb 05, 2021 4:26 pm
- Forum: Student Social/Study Group
- Topic: Study routine.
- Replies: 51
- Views: 2151
Re: Study routine.
Going over the outline is very helpful! It leads me to the right direction of which things I should focus on. I then practice the textbook problems so that I know how to tackle those types of problems if they were to appear on an exam. It truly is all about practicing and creating a habit out of it.
- Thu Jan 28, 2021 12:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Factors that affect the equilibrium constant
- Replies: 31
- Views: 3877
Re: Factors that affect the equilibrium constant
Changing the temperature towards either a melting or freezing point will change the equilibrium constant K!
- Thu Jan 28, 2021 12:00 pm
- Forum: Phase Changes & Related Calculations
- Topic: Define Phase Change
- Replies: 78
- Views: 4745
Re: Define Phase Change
A phase change is when a substance changes to another state. Ex. liquid to gas. Certain temperatures cause this change, such as melting or boiling point.
- Thu Jan 28, 2021 11:54 am
- Forum: Identifying Acidic & Basic Salts
- Topic: Will buffer solutions be on the midterm?
- Replies: 4
- Views: 323
Re: Will buffer solutions be on the midterm?
^To add on, the outlines are truly helpful to review as they show the material that is expected to be on the midterm!
- Thu Jan 28, 2021 11:52 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Sapling week 4 question 15
- Replies: 2
- Views: 82
Re: Sapling week 4 question 15
Volume expansion work against a constant pressure is
w=-pV
w= -1.013 *10^5 N/m^2 * 6.32*10^-3 m^3 = -640 J
w=-pV
w= -1.013 *10^5 N/m^2 * 6.32*10^-3 m^3 = -640 J
- Thu Jan 28, 2021 11:47 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Chem 14B Midterm Week 4
- Replies: 3
- Views: 135
Re: Chem 14B Midterm Week 4
The last lecture you should study for is week 3's friday lecture! Week 4 material will not be on this midterm.
- Fri Jan 22, 2021 3:41 pm
- Forum: Phase Changes & Related Calculations
- Topic: Constant Temperature
- Replies: 20
- Views: 687
Re: Constant Temperature
The temperature remains consistent as the bonds are being broken. Despite heat being added, it is not being conserved.
- Fri Jan 22, 2021 3:40 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka correlation to strength of an acid
- Replies: 30
- Views: 2046
Re: Ka correlation to strength of an acid
The acid is stronger when Ka is greater.
- Fri Jan 22, 2021 12:05 am
- Forum: Phase Changes & Related Calculations
- Topic: Steam causing severe burns
- Replies: 19
- Views: 753
Re: Steam causing severe burns
To further add on to this discussion, it makes sense why steam coming from hot water would not cause severe burns because it would have come into contact with cooler air. However, if steam was coming from an enclosed space, such as a pipeline, it would more than likely cause more damage because the ...
- Thu Jan 21, 2021 11:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm 1: Lecture cutoff
- Replies: 8
- Views: 256
Re: Midterm 1: Lecture cutoff
Tomorrow's lecture will be the cutoff for midterm 1! Therefore, we will have the weekend to look over content that we learned weeks 1-3.
- Thu Jan 21, 2021 11:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Studying for Midterm #1
- Replies: 63
- Views: 2346
Re: Studying for Midterm #1
For the first midterm in Chem 14A, a lot of the problems were similar to the textbook problems. Hopefully the first midterm for Chem 14B is similar to that one, but all the resources provided should be useful. None of the questions will contain content we haven't already seen.
- Sun Jan 17, 2021 1:48 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: How do we know a compound is a weak acid or base?
- Replies: 6
- Views: 338
Re: How do we know a compound is a weak acid or base?
Most acids and bases are weak, meaning that they do not completely dissociate into its ions, when we place them in solution. Only a few acids and bases are strong. Therefore, memorizing key ones could be used to your advantage.
- Sun Jan 17, 2021 1:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D9: deprotonation
- Replies: 1
- Views: 75
Re: 6D9: deprotonation
Hey! Deprotonation, by definition, is the removal (transfer) of a proton (H+) from a Brønsted–Lowry acid in an acid-base reaction. The complementary process, when a proton is added (transferred) to a Brønsted–Lowry base, is protonation (or hydronation). Percent deprotonation is the percentage of the...
- Sun Jan 17, 2021 1:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Textbook Problem 5I.19
- Replies: 2
- Views: 160
Re: Textbook Problem 5I.19
Hey! So for the percentage, it says that 60% of the hydrogen has reacted, which means 40% remains. You can find the change in concentration of H2 at equilibrium with (.400)(0.133mol/L-x). If you subtract the original concentration value by 40%, you will end up with the 60%. You want to use the 40%, ...
- Sun Jan 17, 2021 12:34 pm
- Forum: General Science Questions
- Topic: class 1/18/21
- Replies: 13
- Views: 637
Re: class 1/18/21
We don't have class tomorrow! Enjoy the day. Get some fresh air.
- Sun Jan 17, 2021 12:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework Problem 5I.19
- Replies: 1
- Views: 106
Re: Homework Problem 5I.19
Hey! For the percentage, it says that 60% of the hydrogen has reacted, which means 40% remains. You can find the change in concentration of H2 at equilibrium with (.400)(0.133mol/L-x). If you subtract the original concentration value by 40%, you will end up with the 60%. You want to use the 40%, by ...
- Sun Jan 10, 2021 3:57 pm
- Forum: Ideal Gases
- Topic: Units of Temperature
- Replies: 82
- Views: 3213
Re: Units of Temperature
Kelvins are always used. You can convert Celsius to Kelvin by adding 273.15
- Sun Jan 10, 2021 3:53 pm
- Forum: Student Social/Study Group
- Topic: New Year Resolutions?
- Replies: 54
- Views: 2477
Re: New Year Resolutions?
Read more books and practice more self love.
- Sun Jan 10, 2021 3:20 pm
- Forum: Student Social/Study Group
- Topic: Chemistry Community
- Replies: 29
- Views: 1076
Chemistry Community
What's the weekly deadline for posting on chemistry community in order to earn your 5 points of the day? Or can we still manage to gain the points during the upcoming week?
- Sun Jan 10, 2021 3:17 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Are there reactions that just do not/ can not ever reach equilibrium?
- Replies: 18
- Views: 1630
Re: Are there reactions that just do not/ can not ever reach equilibrium?
Everything that goes up, must come down. Therefore, I believe almost every reaction must reach a certain equilibrium in order to be executed properly.
- Sun Jan 10, 2021 3:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Question about 14B Exams
- Replies: 38
- Views: 1235
Re: Question about 14B Exams
Yes, midterms will be administered during lecture time, as opposed to discussion time. Everyone will be taking it at the same time in order to reduce any unfair advantages.
- Fri Dec 11, 2020 12:17 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Sapling Week 10 #13
- Replies: 7
- Views: 389
Re: Sapling Week 10 #13
The predominant species is neutral because the the pH level is less than the pKa.
- Thu Dec 10, 2020 8:20 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: Sapling HW 10 Question 11
- Replies: 6
- Views: 360
Re: Sapling HW 10 Question 11
Therefore, HCIO is considered to be the most acidic, while HIO is the least acidic.
- Thu Dec 10, 2020 6:31 pm
- Forum: Air Pollution & Acid Rain
- Topic: Why does acid rain exist
- Replies: 16
- Views: 981
Re: Why does acid rain exist
Acid rain occurs when compounds like sulfur dioxide and nitrogen oxides are released into the air, from vehicles and factories, and they rise up into the atmosphere to mix with chemicals like water and oxygen to form this acidic pollutant. Typical acid rain has a pH level 4.0.
- Thu Dec 10, 2020 6:18 pm
- Forum: Student Social/Study Group
- Topic: Anxiety
- Replies: 109
- Views: 6694
Re: Anxiety
Planning out a schedule of topics to study over helps me feel less overwhelmed. Taking breaks and changing settings also helps reduce my anxiety. Only a few more days left, you got this!
- Wed Dec 09, 2020 4:20 pm
- Forum: Bronsted Acids & Bases
- Topic: 6C.21 Which acid is stronger?
- Replies: 1
- Views: 127
Re: 6C.21 Which acid is stronger?
In acetic acid, you have CH3 bonded to COOH, whereas in formic acid, only H is bonded to COOH. The CH3 group in acetic acid has electron-donating properties, which means it is less electron withdrawing power than the H attached to COOH in formic acid. Thus, formic acid is slightly stronger than acet...
- Fri Dec 04, 2020 10:44 pm
- Forum: Bronsted Acids & Bases
- Topic: Textbok Problem J.1
- Replies: 4
- Views: 368
Re: Textbok Problem J.1
A bronstead acid is a proton donor and a bronstead base is a proton receiver.
a) NH3 has a lone pair of electrons in Nitrogen, which accepts protons.
b) HBr wants to donate its hydrogen
etc....
Hope this helps!
a) NH3 has a lone pair of electrons in Nitrogen, which accepts protons.
b) HBr wants to donate its hydrogen
etc....
Hope this helps!
- Fri Dec 04, 2020 10:30 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Question 2
- Replies: 4
- Views: 256
Re: Sapling Question 2
^That tip is very helpful, I was able to solve this question in 2 attempts. The subscripts inside the brackets are the only ones to take into consideration.
- Fri Dec 04, 2020 9:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.13 Part D, Determining the bond angle of N2O
- Replies: 5
- Views: 479
Re: 2E.13 Part D, Determining the bond angle of N2O
I'm not sure where the .5 came from, but it should definitely be 180.
- Fri Dec 04, 2020 9:51 pm
- Forum: Student Social/Study Group
- Topic: Practice Exam for Final
- Replies: 23
- Views: 1102
Re: Practice Exam for Final
Looking over the textbook problems might be helpful for studying. However, it didn't really help for the last midterm, but hopefully this final goes better!
- Fri Dec 04, 2020 9:31 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sapling HW 9 Problem #6
- Replies: 3
- Views: 198
Re: Sapling HW 9 Problem #6
Yes, you would have two take into account the Cl outside of the brackets. In this problem, the oxidative state of [Co (NH3)5 Cl] Cl will be 3+
- Tue Nov 24, 2020 10:57 pm
- Forum: Student Social/Study Group
- Topic: Sapling wk 8 AsO3−4 lewis structure
- Replies: 3
- Views: 263
Re: Sapling wk 8 AsO3−4 lewis structure
You might have forgotten to add the (-) charge on the three oxygens, not including the one with the double bond.
- Tue Nov 24, 2020 10:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 8 Participation Points
- Replies: 6
- Views: 368
Re: Week 8 Participation Points
Yes, in the email he sent earlier today, he mentions that chemistry community would still be up and running on Thursday & Friday.
- Tue Nov 24, 2020 10:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.7
- Replies: 3
- Views: 117
Re: 2E.7
I think the shape gives an approximation of the angle, so you are correct. Since it is a trigonal pyramidal, the angles will be slightly less than 109.5
- Tue Nov 24, 2020 7:44 pm
- Forum: Student Social/Study Group
- Topic: Final Format
- Replies: 35
- Views: 1507
Re: Final Format
The believe the final will have the same structure as the past 2 midterms, just with more questions and more time.
- Tue Nov 24, 2020 7:34 pm
- Forum: Student Social/Study Group
- Topic: Big Sad: Midterm 2
- Replies: 86
- Views: 5343
Re: Big Sad: Midterm 2
I did not do as well as I anticipated, but I guess I have to do my very best on the final! There's still hope, hopefully.
- Thu Nov 19, 2020 6:40 pm
- Forum: General Science Questions
- Topic: Midterm 2
- Replies: 8
- Views: 544
Re: Midterm 2
The setup will be the same way as midterm 1, with a separate device/camera for zoom and respondus lockdown browser on a computer.
- Thu Nov 19, 2020 6:38 pm
- Forum: Trends in The Periodic Table
- Topic: atomic radius of anions
- Replies: 9
- Views: 465
Re: atomic radius of anions
In the periodic table, the atomic radius decreases along a row from left to right, but increases in a group from top to bottom. Br is found further down the periodic table than Na, so the atomic radius is larger for Br, despite it being on the further right side of the periodic table.
- Thu Nov 19, 2020 6:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 8 Chem 14A Friday Lecture
- Replies: 7
- Views: 400
Re: Week 8 Chem 14A Friday Lecture
I doubt we will have a video lecture for Friday, but I would just recommend keeping a look out for it. We're almost done!
- Thu Nov 19, 2020 6:25 pm
- Forum: Dipole Moments
- Topic: What are dipole moments
- Replies: 9
- Views: 611
Re: What are dipole moments
The dipole moment is a measurement of the polarity of a molecule. The larger the difference in electronegativity, the larger the dipole moment. I'm sure you can find more info on youtube videos!
- Thu Nov 19, 2020 6:23 pm
- Forum: Lewis Structures
- Topic: Lone pair
- Replies: 2
- Views: 193
Re: Lone pair
I believe you are correct. You can find lone pair # by getting valence electron - 8n / 2.
- Fri Nov 13, 2020 12:46 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Repulsion
- Replies: 9
- Views: 429
Re: Repulsion
Lone pairs have a stronger repulsion than bonding pairs because the bonding pairs are further away from the central atom, while lone pairs are closer to the nucleus, so it will give off more repulsion.
- Fri Nov 13, 2020 12:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: The shape
- Replies: 5
- Views: 311
Re: The shape
I think the molecule with the highest electronegativity should be in the middle, while the others are around it. This would just make it easier to construct the shape. Or you could just go based how many molecules there are.
- Fri Nov 13, 2020 11:06 am
- Forum: Dipole Moments
- Topic: Boiling point of molecules
- Replies: 5
- Views: 273
Re: Boiling point of molecules
Tetrachloromethane has a higher boiling point because it has more electrons, so it has a larger molecular surface area which increases the intermolecular interaction strength.
- Fri Nov 13, 2020 10:44 am
- Forum: Lewis Structures
- Topic: Double Bonds
- Replies: 11
- Views: 258
Re: Double Bonds
To further emphasize what the previous person said, Cl never has a double bond because it is just not stable enough to have that. Oxygen is most likely to carry this, so that it a helpful tip to know! But it would usually go to the element with the least formal charge.
- Fri Nov 13, 2020 10:41 am
- Forum: Student Social/Study Group
- Topic: Test Anxiety
- Replies: 62
- Views: 2858
Re: Test Anxiety
Usually before a test I get really anxious because I feel like I won't have enough time, but I take deep breathes and trust in myself. If I come across a problem that I don't understand right away, I move on to the next. Usually when I come back to it in the end, I'm more likely to remember it! Paci...
- Fri Nov 06, 2020 12:26 pm
- Forum: Lewis Structures
- Topic: Textbook 2A. 23
- Replies: 5
- Views: 162
Re: Textbook 2A. 23
I don't think memorization is required, the periodic table is helpful.
To follow on the previous response, B) indium(III) sulfide, Indium is +3 and sulfide -2, so to balance the charges, you will have In2S3
To follow on the previous response, B) indium(III) sulfide, Indium is +3 and sulfide -2, so to balance the charges, you will have In2S3
- Fri Nov 06, 2020 11:44 am
- Forum: Octet Exceptions
- Topic: Exceptions
- Replies: 9
- Views: 346
Re: Exceptions
I think being able to recognize or understand what makes an atom an exception is best. But knowing some like Be and B could be just as helpful, but I doubt memorizing all of them is necessary.
- Fri Nov 06, 2020 11:40 am
- Forum: Student Social/Study Group
- Topic: Favorite TV shows
- Replies: 277
- Views: 33377
Re: Favorite TV shows
How to Get Away With Murder! Very tense, but the plot twist are amazing.
- Fri Nov 06, 2020 11:31 am
- Forum: Ionic & Covalent Bonds
- Topic: Textbook 2B.13 question
- Replies: 3
- Views: 171
Re: Textbook 2B.13 question
Drawing them out would be your best bet since you can see the bonds between C and H. This practice will be really helpful for future exams!
- Fri Nov 06, 2020 11:19 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Concept of Polarizeable and Polarizing
- Replies: 2
- Views: 82
Re: Concept of Polarizeable and Polarizing
Hey! I believe high polarizability refers to a cations ability to distort an anion while an anion is highly polarizable to become polarized by the cation... If that makes sense. And I believe your other statement is correct, since they have a lower polarizability, that means their electrons are all ...
- Thu Oct 29, 2020 8:59 pm
- Forum: Photoelectric Effect
- Topic: Kinetic Energy
- Replies: 10
- Views: 482
Re: Kinetic Energy
A higher frequency light would emit electrons with higher kinetic energy if and only if the frequency is already high enough for an electron to be ejected. If not, you can't make that assumption, therefore it would be false.
- Thu Oct 29, 2020 8:41 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3d and 4s state
- Replies: 4
- Views: 174
Re: 3d and 4s state
4s contains several peaks within the space of the 3d orbital. As a result, it experiences penetration of the shielding the 3d would otherwise provide, and is pulled closer and thus its energy level is lower.
- Thu Oct 29, 2020 3:41 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Excited State
- Replies: 3
- Views: 261
Re: Excited State
An element enters their excited state when an electron temporarily occupies an energy level greater than its ground state. This occurs when the outer electrons observe energy and jump to a higher orbital. Eventually it can release this energy and fall back to a lower state. During this process, the ...
- Wed Oct 28, 2020 6:26 pm
- Forum: Trends in The Periodic Table
- Topic: Trends in Groups 15 and 16
- Replies: 4
- Views: 240
Re: Trends in Groups 15 and 16
Yes, this trend does apply to elements in different rows. As you move down the rows, the first ionization energy decreases. When you move across the periodic table, the first ionization energy increases.
- Wed Oct 28, 2020 6:11 pm
- Forum: Trends in The Periodic Table
- Topic: Lecture 10/28 Question about S-Block Elements
- Replies: 5
- Views: 214
Re: Lecture 10/28 Question about S-Block Elements
I believe it is important to know that the s-block elements are made out of metal because that is one of the properties that they all share. Collectively, they always lose their valance electron that's in the s-orbital. Because of this, they are considered to be the most reactive elements in the per...
- Fri Oct 23, 2020 6:26 pm
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 14
- Views: 511
Re: Wavelength
I believe they should be converted to nanometers, but you could look at the answer choices to see which units you need to convert the answer to!
- Thu Oct 22, 2020 4:49 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Problem 1D.11
- Replies: 1
- Views: 47
Re: Problem 1D.11
I refers to the number of orbitals in a subshells. I = 1 corresponds to the p-orbital, I=2 corresponds to the d orbital and I=3 to the f-orbital.
- Thu Oct 22, 2020 4:43 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Conceptual difference between momentum and velocity
- Replies: 4
- Views: 438
Re: Conceptual difference between momentum and velocity
The momentum of an object is = to the mass of an object x the velocity. Momentum is a vector, which has the same direction as the velocity.
- Thu Oct 22, 2020 2:36 pm
- Forum: Student Social/Study Group
- Topic: studying for exams
- Replies: 21
- Views: 2305
Re: studying for exams
The problems on Sapling give me a basic foundation of what to expect on the midterm, so I make sure I'm familiar with how to solve these kind of problems. I also look through my notes and review terms that I highlighted because those were emphasized during Dr. Lavelle's lectures. Doing practice prob...
- Thu Oct 22, 2020 2:22 pm
- Forum: *Shrodinger Equation
- Topic: vacuum permittivity
- Replies: 1
- Views: 84
Re: vacuum permittivity
If i'm not mistaken , the vacuum permittivity is the force between two electrons. The value is 8.854 x 10^-12
- Thu Oct 15, 2020 3:10 pm
- Forum: SI Units, Unit Conversions
- Topic: Webcam
- Replies: 11
- Views: 339
Re: Webcam
I believe it is mandated by Dr. Lavelle in order to reduce any unfair advantages during the exams!
- Thu Oct 15, 2020 3:07 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Sapling Wk 2/3 #5
- Replies: 2
- Views: 107
Re: Sapling Wk 2/3 #5
Hey!
The possible number of spectral lines can be found (n2 - n1)(n2-n1 +1) / 2
so: (5-1)(5-1+1)/ 2 = 10
And I'm actually not quite sure how to find the wavelengths, so I would also appreciate the help!
The possible number of spectral lines can be found (n2 - n1)(n2-n1 +1) / 2
so: (5-1)(5-1+1)/ 2 = 10
And I'm actually not quite sure how to find the wavelengths, so I would also appreciate the help!
- Thu Oct 15, 2020 2:51 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Variables in E(n)=-hR/n^2
- Replies: 3
- Views: 160
Re: Variables in E(n)=-hR/n^2
Hey!
E(n) represents the energy of n energy level.. I believe n could stand for either initial and final, depending on the value (such as n=3 went to n =2).. Someone correct me if I'm wrong :)
E(n) represents the energy of n energy level.. I believe n could stand for either initial and final, depending on the value (such as n=3 went to n =2).. Someone correct me if I'm wrong :)
- Tue Oct 13, 2020 4:06 pm
- Forum: Properties of Light
- Topic: Sapling Week 2/3 Homework
- Replies: 3
- Views: 71
Re: Sapling Week 2/3 Homework
Hey!
It's important to remember that energy is proportional to the number of photons, therefore, the wavelength would be λ, with a frequency of v and Energy of 100.
Someone might want to check my answer or further explain it!
It's important to remember that energy is proportional to the number of photons, therefore, the wavelength would be λ, with a frequency of v and Energy of 100.
Someone might want to check my answer or further explain it!
- Tue Oct 13, 2020 3:11 pm
- Forum: Einstein Equation
- Topic: Equation Sheet
- Replies: 15
- Views: 440
Re: Equation Sheet
I believe we will have access to this equation sheet during our midterm in week 4.. I may be wrong tho, might have to ask my TA during my discussion tomorrow
- Tue Oct 13, 2020 2:52 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: 1B.27
- Replies: 3
- Views: 167
Re: 1B.27
Hey!
I believe there is an error in the problem because when I worked it out, I got ∆v = 10.0 m/s instead of 5.0 as the minimum uncertainty of the position is the spread of the values.. I may be off somewhere, someone might have to check my answer!
I believe there is an error in the problem because when I worked it out, I got ∆v = 10.0 m/s instead of 5.0 as the minimum uncertainty of the position is the spread of the values.. I may be off somewhere, someone might have to check my answer!
- Thu Oct 08, 2020 4:28 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Moles textbook problem
- Replies: 3
- Views: 483
Re: Moles textbook problem
First start off by figuring out the formula mass of MgSO4 * 7H2O, which is 246.48 g/mol Then, divide the amount of grams of the sample by the molar mass After finding out the amount of moles of the sample, you can multiply the mole ratio to find the number of moles of oxygen Lastly, multiply by Avog...
- Thu Oct 08, 2020 4:17 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Post Assessment Survey Question Help
- Replies: 3
- Views: 96
Re: Post Assessment Survey Question Help
Your answer is correct Jenny!
The balanced equation I got : 2 C6H6 + 15 O2 --> 12 CO2 + 6 H2O
shows that 15 moles of O2 are required for 2 moles of C6H6 to combust into CO2 and H20
- If it were just 1 mole of C6H6, you would simply need 7.5 moles (15/2) of O2!
The balanced equation I got : 2 C6H6 + 15 O2 --> 12 CO2 + 6 H2O
shows that 15 moles of O2 are required for 2 moles of C6H6 to combust into CO2 and H20
- If it were just 1 mole of C6H6, you would simply need 7.5 moles (15/2) of O2!
- Thu Oct 08, 2020 4:09 pm
- Forum: SI Units, Unit Conversions
- Topic: E 29
- Replies: 2
- Views: 90
Re: E 29
I had the same issue! Could it just be for more precision? Maybe, but my answer for d) was
O = 4(16.00 g / mol) / (206.53 g/mol) = 0.3099
*Total mass of sample due to oxygen*
O = 4(16.00 g / mol) / (206.53 g/mol) = 0.3099
*Total mass of sample due to oxygen*