Search found 64 matches

by Cooper_Geralds_3B
Sun Jan 17, 2021 4:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa and pH
Replies: 3
Views: 19

Re: pKa and pH

Hi! I hope this helps

pKa= -log(Ka) and pH= -log (H3O+)
and pKa + pKb = 14
by Cooper_Geralds_3B
Sun Jan 17, 2021 4:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading for Chemistry Community Posts
Replies: 6
Views: 35

Re: Grading for Chemistry Community Posts

Hi! I believe it depends when your specific TA plans on checking for your posts but I would just try your best to do 5 posts/week so that you can use chem community as a resource for homework, study, concept help throughout the course rather than just cramming in random posts for points towards the ...
by Cooper_Geralds_3B
Sun Jan 17, 2021 4:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam Format
Replies: 13
Views: 63

Re: Exam Format

Hi! The exam format will likely be multiple choice including concepts and calculations depending on the units covered. We will likely have lockdown browser and have to zoom our TAs with an external device such as a phone so that they can monitor our hand movement. You should print out the equation s...
by Cooper_Geralds_3B
Sun Jan 17, 2021 3:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Registering/Creating Your Chemistry Community Account
Replies: 32
Views: 44962

Re: Registering/Creating Your Chemistry Community Account

I haven't been able to register until now, could I make up the points by posting more this week? Hi! You should be able to, last quarter in 14a, the TAs generally only calculated the total mid quarter and at the end, but if you contact your TA and let them know your technological circumstances I am...
by Cooper_Geralds_3B
Sun Jan 17, 2021 3:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Accessing the E-textbook [ENDORSED]
Replies: 103
Views: 7134

Re: Accessing the E-textbook [ENDORSED]

Pretty sure that Sapling is mandatory, and will actually be collected midnight of the following Sunday, however, is this the only "homework" due?? Yes sapling is the only homework that is taken for a grade, but the extra homework problems that Dr. Lavelle lists on the syllabus and chapter...
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:46 pm
Forum: Ideal Gases
Topic: Units of Temperature
Replies: 82
Views: 286

Re: Units of Temperature

Juwan_Madaki_3K wrote:When using the ideal gas law, which units should the temperature be in? Kelvins or Celsius?


I believe most of the time in 14B we will be using Kelvin for temperature unless a specific problem indicates otherwise!
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:44 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8502
Views: 1469570

Re: Post All Chemistry Jokes Here

Did you hear the one about cobalt, radon, and yttrium?

It was ~CoRnY~
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:41 pm
Forum: Ideal Gases
Topic: Reviewing PV=NRT
Replies: 7
Views: 55

Re: Reviewing PV=NRT

Where can we find all the answers to the textbook practice problems? I believe it might be on Lavelle's website but I cannot recall under what tab. Given that this concept requires all sorts of equation solving back and forth it might be a good idea to gain a better grasp by literally applying it i...
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units
Replies: 27
Views: 80

Re: Units

I was wondering why when we calculate partial pressure the answer could be either in bars or moles per liter. Is there any unit out of the two that is preferred? Usually the units preferred are given in the question or you can deduce the best units from the units given! Sometimes on tests as well D...
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B [ENDORSED]
Replies: 103
Views: 1711

Re: Chemistry Posts in 14B [ENDORSED]

What is the last day in the week to get in our 5 posts? Is there a set "due date"? Last quarter in 14A, the chemistry community posts were only added up every few weeks, so I would try to do 5/week just to stay on track but it should also be okay if you end up doing more some weeks and le...
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B [ENDORSED]
Replies: 103
Views: 1711

Re: Chemistry Posts in 14B [ENDORSED]

Sarah Huh 1K wrote:I'm not sure if someone already asked this, but will there be any modules for future lessons?


If it is the same as 14A, then the only modules for the whole quarter are the ones that are already posted on Dr. Lavelles 14B site.
by Cooper_Geralds_3B
Sun Jan 10, 2021 3:32 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B [ENDORSED]
Replies: 103
Views: 1711

Re: Chemistry Posts in 14B [ENDORSED]

Massimo_Capozza_1G wrote:Also is there a way to sort between Chem 14A and Chem 14B posts?


Hi yes! If you click on board index, Dr. Lavelle has separated the topics into 14A and 14B, and then when you look at your posts I believe the only way to distinguish them is by the date.
by Cooper_Geralds_3B
Tue Dec 08, 2020 8:12 am
Forum: Student Social/Study Group
Topic: Finals Study Things
Replies: 27
Views: 182

Re: Finals Study Things

Thank you so much! It is so nice to have everything organized into one neat simple document with hyperlinks, this really helped decrease my stress in regards to organizing all of the topics!
by Cooper_Geralds_3B
Tue Dec 08, 2020 8:08 am
Forum: Student Social/Study Group
Topic: How to study for class
Replies: 30
Views: 177

Re: How to study for class

I am wondering if anyone has found a good way to study conceptual topics? I always find myself second guessing myself on the exam questions that are more concept based rather than numerical or calculation based.
by Cooper_Geralds_3B
Mon Dec 07, 2020 8:47 pm
Forum: Calculating the pH of Salt Solutions
Topic: -OH vs OH-
Replies: 12
Views: 89

Re: -OH vs OH-

Hi, I noticed the -OH in today's lecture as well and am used to seeing OH- in both his lectures and the homework, but I am pretty certain that they are the same!
by Cooper_Geralds_3B
Mon Dec 07, 2020 8:42 pm
Forum: Bronsted Acids & Bases
Topic: acid strength
Replies: 3
Views: 40

Re: acid strength

Hi! I found this from sapling textbook which is a helpful list of strong acids and bases, and essentially every other acid or base not listed is considered weak.
by Cooper_Geralds_3B
Mon Dec 07, 2020 11:17 am
Forum: Administrative Questions and Class Announcements
Topic: Potential Problem with Lecture #28 Upload
Replies: 1
Views: 43

Potential Problem with Lecture #28 Upload

Hi,

I am currently trying to watch today's uploaded lecture #28, but there is an error coming up saying "this video file cannot be played. Error:232001". I was wondering if anyone else is running into this issue or if this might be an issue on my end with my computer.

Thank you.
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:45 am
Forum: Student Social/Study Group
Topic: How to study for class
Replies: 30
Views: 177

Re: How to study for class

Hi! I find the extra textbook problems and sapling to be the best as far as simulating test questions, and then I try to find khan academy videos for concepts that I do not understand fully.
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:42 am
Forum: Student Social/Study Group
Topic: Week 8/9 Thoughts/Worries
Replies: 66
Views: 478

Re: Week 8/9 Thoughts/Worries

I feel like the hardest part for me is grasping the conceptual material for the exams, I feel like there are always questions that surprise me when it comes to the concepts. Do you guys have any good ways or sources to review the conceptual material for the final?
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:39 am
Forum: Student Social/Study Group
Topic: Calculating grade
Replies: 24
Views: 242

Re: Calculating grade

If we complete the sapling assignments by the due dates are we guaranteed the full 50 points for that portion of our grades?
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:36 am
Forum: Student Social/Study Group
Topic: How are you?
Replies: 111
Views: 753

Re: How are you?

I was really stressed that I would not end up getting the classes that I need for winter quarter, but I ended up getting them which is such a relief! I am curious, how do you guys plan on reviewing for the final? I want to start reviewing soon so that I avoid the stress of cramming a few days in adv...
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:34 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 8
Views: 54

Re: Coordination Number

Hi, here is a helpful definition that I found on coordination numbers: "Coordination number, also called Ligancy, the number of atoms, ions, or molecules that a central atom or ion holds as its nearest neighbors in a complex or coordination compound or in a crystal" (Britannica). Hope this...
by Cooper_Geralds_3B
Thu Dec 03, 2020 9:33 am
Forum: Naming
Topic: Writing it out
Replies: 4
Views: 24

Re: Writing it out

Hi! In discussion yesterday, I learned that cations (+) come before and anions (-) come after!
by Cooper_Geralds_3B
Sun Nov 29, 2020 3:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #2
Replies: 2
Views: 31

Re: Sapling #2

Hi! I think that the electron pairs look like this because they drew the lewis structure to resemble the molecular structure, but I do not think this is required. Also, it is linear because there are two regions of electron density, the hybridization is sp and therefore the bond angels are 180 degre...
by Cooper_Geralds_3B
Fri Nov 27, 2020 12:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: trigonal planar vs trigonal pyramidal
Replies: 9
Views: 62

Re: trigonal planar vs trigonal pyramidal

I believe that trigonal planar has 3 regions of electron density and the bond angels are 120 degrees whereas trigonal pyramidal has 4 regions of electron density and has bond angels of 109.5 degrees.
by Cooper_Geralds_3B
Fri Nov 27, 2020 12:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 25
Views: 133

Re: Bond Angles

Here is a helpful summary of the molecular structures that we have done so far and their corresponding bond angles. Please feel free to add to this list! -linear 180 degrees -trigonal planar 120 degrees, -trigonal pyramidal 109.5 degrees -trigonal bipyramidal 90 degrees, 120 degrees -octahedral 90 d...
by Cooper_Geralds_3B
Tue Nov 24, 2020 3:39 pm
Forum: Student Social/Study Group
Topic: Big Sad: Midterm 2
Replies: 86
Views: 859

Re: Big Sad: Midterm 2

I also felt like the second midterm was a bit more challenging, not necessarily because of harder concepts but because for me it is hard to think through the number of problems we had in 50 minutes especially not being able to mark up a paper and do the process of elimination by crossing things out....
by Cooper_Geralds_3B
Mon Nov 16, 2020 4:27 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Valence Electron Question
Replies: 3
Views: 64

Re: Valence Electron Question

Hi, when looking on the periodic table, the number of the element group is at the very top. You can follow these numbers in order with groups 1, 2, skip to 13 (and then look at the second # in double digits for example 3 in 13), 14, 15, 16, 17, 18 to figure out the number of valence electrons in eac...
by Cooper_Geralds_3B
Mon Nov 16, 2020 4:24 pm
Forum: Coordinate Covalent Bonds
Topic: Hydrogen Bonding
Replies: 5
Views: 46

Re: Hydrogen Bonding

Hi! I have these notes written down that summarize hydrogen bonding that is repetitive but might help you: -N,O, or F shares a lone pair of e- with positively polarized (electron-deficient) H -partially positive H is bonded to a partially negative N, O, or F -There must be one of these three bonds: ...
by Cooper_Geralds_3B
Mon Nov 16, 2020 4:20 pm
Forum: Student Social/Study Group
Topic: Winter 2021 Classes
Replies: 20
Views: 217

Re: Winter 2021 Classes

Thank you! Also, would it be okay to take the Chem 14BL Lab section from 11am-1:30pm on Friday even though it goes into Chem 14B's friday lecture at 1pm, since the lecture is recorded? Yes! When enrolling, you might get an error notification due to the overlap but you can quickly bypass it by click...
by Cooper_Geralds_3B
Mon Nov 16, 2020 4:19 pm
Forum: Lewis Structures
Topic: 2B.1 lewis structure part b
Replies: 5
Views: 42

Re: 2B.1 lewis structure part b

This is the most stable structure. If Cl were to have two bonds and then two lone pairs, its formal charge would be 7-(4+4/2) which equals +1. so when drawing structures, we should always just go with what gives us the most stable configuration regardless of the atom's electronegativity? yes! Also ...
by Cooper_Geralds_3B
Mon Nov 16, 2020 4:16 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 11
Views: 94

Re: Resonance

Hi! Generally the resonance structure with a formal charge closest to zero is the most stable structure! Try to see if the charges on each atom cancel each other out, and if they do, this is a good indicator that the formal charge is zero and the structure is stable!
by Cooper_Geralds_3B
Wed Nov 11, 2020 9:27 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: Sapling #20
Replies: 2
Views: 37

Sapling #20

"Select which intermolecular forces of attraction are present between CH3CHO molecules" How do you determine what intermolecular forces of attraction are present just by given the molecular formula?
by Cooper_Geralds_3B
Wed Nov 11, 2020 8:54 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Helpful screenshot of oxidation rules from textbook
Replies: 7
Views: 67

Helpful screenshot of oxidation rules from textbook

I attached a screenshot from the textbook of a helpful list of oxidation rules for calculating oxidation numbers! hope it helps!
by Cooper_Geralds_3B
Wed Nov 11, 2020 4:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Audio-Visual Modules for MD 2 Material?
Replies: 5
Views: 41

Audio-Visual Modules for MD 2 Material?

Hi,
I was wondering if there will be any audio-visual modules for MD2 topics? Right now, the last module is on the Heisenberg Uncertainty Principle.
by Cooper_Geralds_3B
Wed Nov 11, 2020 4:27 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: Helpful Summary of What Induced Dipole- Induced Dipole depends on
Replies: 6
Views: 73

Helpful Summary of What Induced Dipole- Induced Dipole depends on

Hi, Please feel free to add on to this if I leave anything out, but it was helpful to me to make a bullet point list of all of the things that strength of induced dipole-induced dipole interactions depends on to understand the concept. -polarizability of molecule 1 and 2 (a1a2), distance between 2 m...
by Cooper_Geralds_3B
Tue Nov 10, 2020 3:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Week 6 Discussion Question- Cobalt
Replies: 1
Views: 16

Week 6 Discussion Question- Cobalt

In discussion section today, we were asked what element has the electron [Ar]3d^7 and were given that it is M^2+. Can anyone explain why the answer is cobalt? I thought that if we were given ^2+ we would move two to the left on the periodic table because it is two less electrons but cobalt is two to...
by Cooper_Geralds_3B
Tue Nov 10, 2020 3:36 pm
Forum: Trends in The Periodic Table
Topic: Which directions do cation and anions of elements move?
Replies: 3
Views: 29

Which directions do cation and anions of elements move?

For example, would Br^-2 be two to the right on the periodic table or two to the left of the normal Br?
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:41 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration helpful videos
Replies: 1
Views: 14

Electron Configuration helpful videos

Hi, I might be the only one but I was struggling to understand electron configurations in the lecture but I found a couple of helpful youtube videos that I will paste below if anyone wants a quick review or summary on how to do electron configurations! I hope this is helpful. https://www.youtube.com...
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:21 am
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 4
Views: 34

Re: Drawing Lewis Structures

Hi, Dr. Lavelle mentioned in week 4 lecture 3 that you should arrange the lewis structures by choosing the atom with the lowest ionization energy as the central atom and arrange atoms symmetrically around the central atom. It is important to remember that Hydrogen is never a central atom and as far ...
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:17 am
Forum: Trends in The Periodic Table
Topic: Electron affinity and Ionization energy
Replies: 7
Views: 60

Re: Electron affinity and Ionization energy

Hi, ionization energy is the energy required to remove an electron from an atom whereas electron affinity is the energy released when an electron is added to an atom. On a periodic table, both ionization energy and electron affinity decreases down a group and increases across a period.
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:13 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble Gas Configuration
Replies: 13
Views: 75

Re: Noble Gas Configuration

Hi, going off of your question, I am wondering if anyone has a trick or anything on how they remember how to do electron configurations for different compounds?
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:12 am
Forum: Trends in The Periodic Table
Topic: Ionization Energy
Replies: 5
Views: 28

Re: Ionization Energy

Hi, I believe that ionization energy increases that means it is increasingly more difficult to remove an electron. As you move across a period, ionization energy increases, this is because as you move across the period- the atomic radius decreases. As the atomic radius decreases, the atom is essenti...
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:08 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 206
Views: 15620

Re: Advice from a Medical Student - Part II [ENDORSED]

Hi, I am wondering how you went about getting in all the classes that you needed for your undergraduate major at UCLA while also making sure to get in extra classes needed for pre-reqs of med school. Furthermore, how should I go about making sure I am meeting all the course requirements at various m...
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:05 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm grades
Replies: 5
Views: 68

Re: Midterm grades

Hi, yesterday in Office Hours, Dr. Lavelle said that scores should be out this Thursday!
by Cooper_Geralds_3B
Tue Nov 03, 2020 10:04 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm Scores
Replies: 28
Views: 268

Re: Midterm Scores

Hi, in office hours yesterday Dr. Lavelle said that scores for midterm 1 should be out this week Thursday 11/5!
by Cooper_Geralds_3B
Tue Oct 27, 2020 6:11 pm
Forum: *Shrodinger Equation
Topic: For Ms (spin up, spin down)
Replies: 6
Views: 81

For Ms (spin up, spin down)

For the value of Ms, is there an arrow always given to indicate whether it is spin up or spin down or is there another way to determine whether the value is + or -1/2?
by Cooper_Geralds_3B
Wed Oct 21, 2020 5:23 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework up to Q19 and Midterm 1 [ENDORSED]
Replies: 7
Views: 137

Re: Homework up to Q19 and Midterm 1 [ENDORSED]

I am wondering if sapling is not in the same order for everyone because some of my questions 1-19 do cover material we have not yet learned such as quantum numbers and some questions past 19 cover material that we have learned such as DeBroglie. Is there anyway that a list of the specific questions ...
by Cooper_Geralds_3B
Wed Oct 21, 2020 5:14 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Homework problem #14
Replies: 2
Views: 35

Homework problem #14

Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n=3 to the level n=2. I am getting 12.66 nm as the answer after doing Rydberg's equation, but sampling is saying this answer is incorrect. Is anyo...
by Cooper_Geralds_3B
Wed Oct 21, 2020 2:33 pm
Forum: Administrative Questions and Class Announcements
Topic: The Midterm Topics
Replies: 5
Views: 70

Re: The Midterm Topics

Hi, In discussion today, my TA suggested that we know all the elements that are diatomic, so I thought it would be helpful for me to put them all here if anyone needs them. Hydrogen (H2) Nitrogen (N2) Fluorine (F2) Oxygen (O2) Iodine (I2) Chlorine (Cl2) Bromine (Br2) A sentence I found online said t...
by Cooper_Geralds_3B
Wed Oct 21, 2020 2:30 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Lecture 10/21 Question about H-atom problem
Replies: 3
Views: 21

Lecture 10/21 Question about H-atom problem

Hi, I was wondering if anyone could tell me how Dr. Lavelle found the mass of 9.1 x 10^-31 kg when he was calculating the change in velocity in the following problem: For H-atom the electron is then confined to its nuclear diameter, 1.7 x 10^-15 m (which would be the electron's uncertainty in positi...
by Cooper_Geralds_3B
Wed Oct 21, 2020 9:18 am
Forum: Empirical & Molecular Formulas
Topic: Diatomic Elements
Replies: 3
Views: 21

Diatomic Elements

Hi, Does anyone know when we should make sure to calculate elements in their diatomic forms? For example, when finding calculating for empirical and molecular formulas, is there ever a time that we would not double the mass of nitrogen, oxygen, or any of the other elements that only exist in diatomi...
by Cooper_Geralds_3B
Mon Oct 19, 2020 7:27 pm
Forum: DeBroglie Equation
Topic: At What Point does wavelength become undetectable?
Replies: 8
Views: 75

Re: At What Point does wavelength become undetectable?

Hi, Dr. Lavelle said that anything shorter than 10^-15 m is not detectable. I also researched further and found that the longest detectable wavelengths is generally from 10^6 to 10^11 m, but also make sure to pay attention to your units!
by Cooper_Geralds_3B
Mon Oct 19, 2020 7:11 pm
Forum: Properties of Light
Topic: Planck's Constant
Replies: 7
Views: 51

Planck's Constant

Hi,

I must have missed this in lecture, but does anyone know the numerical value of Planck's constant?
by Cooper_Geralds_3B
Sat Oct 17, 2020 1:36 pm
Forum: Student Social/Study Group
Topic: Discussion 2E groupme
Replies: 1
Views: 30

Discussion 2E groupme

Hi is there a groupme for discussion 2E yet?
by Cooper_Geralds_3B
Wed Oct 14, 2020 2:42 pm
Forum: Empirical & Molecular Formulas
Topic: Discussion problem help
Replies: 4
Views: 51

Discussion problem help

194 g/mol of 0.376 g of caffeine burned, 0.682 g CO2, 0.174 g H2O, 0.110 g N2 formed. Determine empirical and molecular formula, write equation for combustion. I started by finding the grams of H and got 0.0196 through dimensional analysis, but I am wondering how to go about finding grams for carbon...
by Cooper_Geralds_3B
Wed Oct 14, 2020 1:33 pm
Forum: Molarity, Solutions, Dilutions
Topic: E 29 part c
Replies: 12
Views: 1494

Re: E 29 part c

Hi, we did this problem in discussion today but I missed the answers. For part a) I ended up getting 0.0423 moles and I was wondering why I got a different answer than posted above? I multiplied 8.61 g * (1 mol/ 202.484 g/mol). I got 202.484 g/mol by adding up the molar mass.
by Cooper_Geralds_3B
Wed Oct 14, 2020 1:26 pm
Forum: Molarity, Solutions, Dilutions
Topic: E 29 part c
Replies: 12
Views: 1494

Re: E 29 part c

Hi, we did this problem in discussion today but I missed the answers. For part a) I ended up getting 0.0423 moles and I was wondering why I got a different answer than posted above? I multiplied 8.61 g * (1 mol/ 202.484 g/mol). I got 202.484 g/mol by adding up the molar mass.
by Cooper_Geralds_3B
Sun Oct 11, 2020 1:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Textbook solutions
Replies: 3
Views: 55

Textbook solutions

Hi, I am wondering where I can find or gain access to the solutions manual for the textbook? I am working through the extra problems right now and want to double check my answers.
by Cooper_Geralds_3B
Sun Oct 11, 2020 12:01 am
Forum: SI Units, Unit Conversions
Topic: Unit Rounding
Replies: 11
Views: 79

Re: Unit Rounding

Hi, the general rule for rounding is wait until the very end of the problem to round and follow sig figs unless it is given specifically in the question.
by Cooper_Geralds_3B
Sat Oct 10, 2020 11:58 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling Week 1 #8
Replies: 23
Views: 234

Re: Sapling Week 1 #8

Hi, a great starting point for this problem is to start by forming the molecular formula by counting the number of each element seen in the structure! I had to do research to figure that out, but once you have the molecular formula, you can proceed as you would following the normal steps for determi...
by Cooper_Geralds_3B
Sat Oct 10, 2020 11:55 pm
Forum: Balancing Chemical Reactions
Topic: Balancing equations.
Replies: 35
Views: 733

Re: Balancing equations.

As far as balancing equations, I recommend always starting with the element that is least abundant and then moving to the next least abundant element, and if it ever comes down to needing for example 6.5 as the coefficient to balance one side, use the fractional form of 6.5 --> 13/2 and then multipl...
by Cooper_Geralds_3B
Sat Oct 10, 2020 11:53 pm
Forum: Significant Figures
Topic: Which number determines sig figs of the answer?
Replies: 26
Views: 179

Re: Which number determines sig figs of the answer?

The significant figure depends on what the specific question is asking for, if the question specifically asks about moles then you would refer to the sig fig of the moles given and used throughout the problem.
by Cooper_Geralds_3B
Tue Oct 06, 2020 8:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Turning in textbook problems
Replies: 10
Views: 117

Re: Turning in textbook problems

Correct! Sapling is the only graded homework assignment that needs to be turned in according to the end of the section covered in class. The current due dates are the end of week 1 and the end of week 3. All other textbook problems are optional but will likely help in review for midterms and final.

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