Search found 85 matches
- Mon Mar 11, 2019 11:03 pm
- Forum: Ideal Gases
- Topic: ICE
- Replies: 8
- Views: 732
Re: ICE
We can use the 5% rule to ignore x in the denominator of the fraction that you get from the ICE table
- Mon Mar 11, 2019 11:00 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Unique rate?
- Replies: 7
- Views: 677
Re: Unique rate?
Is this like the elementary steps reactions where you use the coefficient to determine the power of the concentration?
- Mon Mar 11, 2019 10:58 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka/b and pKa/b relationship
- Replies: 2
- Views: 284
Re: Ka/b and pKa/b relationship
pKa and pKb are the -log of Ka and Kb. As the exponent of the K becomes more negative, pKa or b increases
- Mon Mar 04, 2019 8:04 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Kinetics
- Replies: 7
- Views: 812
Re: Kinetics
Will we be performing calculations where we find the derivatives?
- Mon Mar 04, 2019 8:03 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Order of Reaction
- Replies: 5
- Views: 729
Re: Order of Reaction
Do we know how to find the order or will it be given?
- Mon Mar 04, 2019 7:37 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Different k values
- Replies: 3
- Views: 486
Re: Different k values
A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change by decreasing the activation energy of a reaction
- Mon Feb 25, 2019 10:25 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Question 14.25 (Sixth Edition)
- Replies: 3
- Views: 408
Re: Question 14.25 (Sixth Edition)
A greater E on the standard reduction potential list means reduction is more favorable. For example, Lithium is a metal that likes to "give away" its electron so reducing it (adding an electron) is very unfavorable and E is very negative. When E is negative, the reverse reaction is more fa...
- Mon Feb 25, 2019 10:20 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: When to use Platinum
- Replies: 5
- Views: 6251
Re: When to use Platinum
Platinum electrodes are used because they aren't very reactive, so they won't be involved in the oxidation/reduction. We use them when we have two ions involved so that electrons can flow between the cells
- Mon Feb 25, 2019 10:19 am
- Forum: Balancing Redox Reactions
- Topic: Salt Bridges-won't they dissolve?
- Replies: 5
- Views: 848
Re: Salt Bridges-won't they dissolve?
A salt bridge is made of ions that flow into the solutions produced by the oxidation/reduction to prevent charge build-up, allowing electrons to continue flowing between the two cells
- Sun Feb 24, 2019 8:19 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 14.17 6th Edition
- Replies: 1
- Views: 218
14.17 6th Edition
The question is: (a) Write balanced half-reactions for the redox reaction of an acidified solution of potassium permanganate and iron(II) chloride. (b) Write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction (write its cell diagram) There are multiple reduc...
- Sat Feb 23, 2019 12:32 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Material
- Replies: 11
- Views: 1018
Re: Test 2 Material
What number is this in the 6th edition?
- Mon Feb 18, 2019 7:40 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Free Energy
- Replies: 5
- Views: 542
Re: Free Energy
You add similar to Hess's Law, with the sum of the products minus the sum of the reactants
- Mon Feb 18, 2019 7:38 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Free Energy
- Replies: 5
- Views: 542
Re: Free Energy
I believe that delta G is a state function because delta G not is a state function
- Mon Feb 18, 2019 7:36 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy and Molar Ratios
- Replies: 2
- Views: 838
Re: Gibbs Free Energy and Molar Ratios
Do you mean when you are calculating Gibbs free energy and they want you to find it for a certain temperature using Q? in that case, you need to calculate Q and either compare it to K or delta G to 0 to answer the problem
- Mon Feb 18, 2019 7:30 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy vs. Standard Gibbs Free Energy
- Replies: 3
- Views: 426
Re: Gibbs Free Energy vs. Standard Gibbs Free Energy
Gibbs free energy is delta G, and standard is delta G not at certain conditions. I believe it's 1 atm and 273.15 Kelvin
- Tue Feb 12, 2019 12:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 28048
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Can someone explain #4? Is this because q=0 when delta T=0, and w=0 when -PdeltaV=0?
- Tue Feb 12, 2019 11:51 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
- Replies: 179
- Views: 28048
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
katherinemurk 2B wrote:Can someone explain how to do #1. I found the heat gained by the water but without the final temperature of the metal how would I find the specific heat??
Final temperature of the metal and water are equal
- Mon Feb 11, 2019 4:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Midterm [ENDORSED]
- Replies: 49
- Views: 5366
Re: Midterm [ENDORSED]
Reading other people's questions on Chemistry Community about homework problems while I'm doing them helps me a lot because I can see how else to approach the problem
- Mon Feb 11, 2019 4:44 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond enthalpies
- Replies: 10
- Views: 954
Re: Bond enthalpies
I would know the Lewis structure just in case it isn't obvious what kind of bonds are being broken and formed, especially if there is a lot of change between products and reactants
- Mon Feb 11, 2019 4:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Buffers
- Replies: 4
- Views: 830
Re: Buffers
The strong acid/strong base comes from the salt, right?
- Tue Feb 05, 2019 3:48 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Internal Energy
- Replies: 3
- Views: 529
Re: Internal Energy
Do we need to know this for the midterm? It's not on Outline 3
- Mon Feb 04, 2019 6:38 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: reaction constant P
- Replies: 3
- Views: 357
Re: reaction constant P
Changes in pressure and volume most affect gases because the particles move most freely. Changes in pressure and volume would affect gas particle motion more than it would for liquids and solids, so work is only affected a negligible amount for non-gaseous reactions
- Mon Feb 04, 2019 6:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Midterm
- Replies: 12
- Views: 2206
Re: Midterm
Does anyone know if Lyndon is doing a review session for the midterm?
- Mon Feb 04, 2019 6:33 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: U
- Replies: 7
- Views: 673
Re: U
U is a state property because changes in internal energy are functions of final and initial states
- Sat Feb 02, 2019 12:40 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: breaking double bonds?
- Replies: 6
- Views: 1363
Re: breaking double bonds?
If you imagine a double bond as the sigma and pi bond that we learned in 14A, I think it makes sense that you can't just halve the value of a double bond to get the value of a single bond because the first and second bonds hold the atoms together in different ways
- Sat Feb 02, 2019 12:35 pm
- Forum: Phase Changes & Related Calculations
- Topic: U and its relations to work
- Replies: 8
- Views: 872
Re: U and its relations to work
What is the difference between q and delta H?
- Sat Feb 02, 2019 12:30 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Friday Lecture Notes
- Replies: 2
- Views: 310
Friday Lecture Notes
I copied and paraphrased the following information from Friday's slides, but I'm not sure what I meant by this: -reaction constant P: that involves change in number of moles of gas, so P deltaV is significant -reaction constant P: that involves solids/liquids, so P deltaV is significant (calorimetry...
- Tue Jan 29, 2019 10:15 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpy
- Replies: 2
- Views: 315
Re: Bond Enthalpy
Do we use bond enthalpy for 8.51 in the 6th edition? I'm having a hard time with the Lewis structure, and the solution manual doesn't explicitly state that they used the bond enthalpies
- Tue Jan 29, 2019 10:13 pm
- Forum: Phase Changes & Related Calculations
- Topic: Standard State
- Replies: 6
- Views: 1907
Re: Standard State
A periodic table that's color coded by state of matter might help if you want to memorize them, but you don't need to
- Tue Jan 29, 2019 10:12 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Lecture Question
- Replies: 3
- Views: 337
Re: Lecture Question
If you mean delta H formation, I think it's because we measure delta H formation relative to what the compound "normally" is. At 25 degrees Celsius and 1 atm, oxygen is usually O2(g). So, it doesn't take any additional energy to transform O2(g) from O2(g)
- Mon Jan 28, 2019 10:49 am
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy signs
- Replies: 13
- Views: 1802
Re: Enthalpy signs
Another aspect of this is thinking of the heat as a product or reactant, where in an endothermic reaction (+) it would require heat which can be considered as a reactant. In an exothermic reaction (-), where heat is given off, we can think of it as a product. This strategy is also helpful when thin...
- Mon Jan 28, 2019 10:44 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Adiabatic and diathermic walls
- Replies: 4
- Views: 506
Re: Adiabatic and diathermic walls
I think we only need to learn these terms to identify if systems are closed, open, or isolated (like in 6th edition 8.1)
- Mon Jan 28, 2019 10:41 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 8.3 6th Edition: Work being positive and negative
- Replies: 3
- Views: 342
Re: 8.3 6th Edition: Work being positive and negative
Can someone explain why we use 101.325 J/L*atm to convert w into joules for 8.3, but not for w in 8.9?
- Mon Jan 28, 2019 10:39 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 8.3 6th Edition: Work being positive and negative
- Replies: 3
- Views: 342
Re: 8.3 6th Edition: Work being positive and negative
b) work is positive because a force is being applied to it that causes it to change volume
c) change in internal energy is the sum of heat energy and work energy. Since there isn't a change in heat, the change in internal energy is solely the work done on the system
c) change in internal energy is the sum of heat energy and work energy. Since there isn't a change in heat, the change in internal energy is solely the work done on the system
- Mon Jan 21, 2019 9:52 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: buffer questions on test
- Replies: 7
- Views: 566
Re: buffer questions on test
I think the buffer reactions are the calculations with salts that he listed on outline 2
- Mon Jan 21, 2019 9:50 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Conceptual questions
- Replies: 6
- Views: 525
Re: Conceptual questions
Is test 1 the entire outline 2? I could be wrong but I don't remember going over polyprotic acids (last couple exercises in 6th edition) or examples (last bullet points under concepts)
- Mon Jan 21, 2019 9:48 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5%
- Replies: 5
- Views: 552
Re: 5%
if the x (change in concentration) is less than 5% of the initial concentration, you don't have to include "-x" in the denominator when solving the ICE table
- Wed Jan 16, 2019 8:04 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Polyprotic Acids and Bases
- Replies: 2
- Views: 309
Re: Polyprotic Acids and Bases
Will we be solving problems where we take a polyprotic acid and calculate for both dissociation reactions? i.e. for both H2SO4 and HSO4-
- Wed Jan 16, 2019 8:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: partial pressure v concentration
- Replies: 4
- Views: 327
Re: partial pressure v concentration
Is it ok to just write K or do we have to specify which K we are using?
- Wed Jan 16, 2019 7:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice table coefficients [ENDORSED]
- Replies: 6
- Views: 1004
Re: Ice table coefficients [ENDORSED]
Are there any differences in solving ICE tables for acid-base reactions and gases? Other than keeping in mind partial pressures
- Wed Jan 09, 2019 12:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K and Kc
- Replies: 8
- Views: 620
Re: K and Kc
Do we need to memorize the formula in the book for converting between the 2?
- Wed Jan 09, 2019 12:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: "lie to the right" vs "shifted to the right"
- Replies: 6
- Views: 1476
Re: "lie to the right" vs "shifted to the right"
I think both phrases mean that "to the right" has more products than reactants since products are on the right side of the equilibrium equation
- Tue Jan 08, 2019 7:53 am
- Forum: Student Social/Study Group
- Topic: Changing Discussions Sections
- Replies: 2
- Views: 275
Changing Discussions Sections
I couldn’t find a specific forum to post about changing discussion sections, so I’m posting here. I’m in discussion 2A (T 8-9) and I’m looking to change into discussion 2E because of class conflicts. Is anyone willing to switch?
- Sun Dec 09, 2018 9:02 am
- Forum: Naming
- Topic: polydentate ligands
- Replies: 1
- Views: 1640
Re: polydentate ligands
you put "bis" to replace "di" if the ligand already has "di" in its name (ex: ethylene diamine)
- Fri Dec 07, 2018 8:32 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6th Edition Ch12 #49
- Replies: 1
- Views: 221
6th Edition Ch12 #49
Which is the stronger base, the hypobromite ion, BrO-,or morphine, C17H19O3N? Justify your answer.
Is there a way to solve for this without using data from the textbook? The answer key just lists the pKb
Is there a way to solve for this without using data from the textbook? The answer key just lists the pKb
- Mon Dec 03, 2018 2:17 pm
- Forum: Naming
- Topic: Latin Names
- Replies: 5
- Views: 851
Re: Latin Names
If so, I assume that we would need to know everything on the periodic table that is commonly used. However the periodic table on his website has both the name of the element used and the symbol
- Mon Dec 03, 2018 2:14 pm
- Forum: Naming
- Topic: Latin Names
- Replies: 5
- Views: 851
Re: Latin Names
Are you referring to something like silver versus Ag?
- Mon Dec 03, 2018 2:13 pm
- Forum: Naming
- Topic: Water as a ligand
- Replies: 4
- Views: 206
Re: Water as a ligand
Will we get marked off if we don't write OH2?
- Sun Dec 02, 2018 11:44 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted v. Lewis v. Arrhenius
- Replies: 4
- Views: 700
Re: Bronsted v. Lewis v. Arrhenius
thanks! this is very helpful because I was confused as well
- Sun Dec 02, 2018 11:43 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong Bases
- Replies: 3
- Views: 482
Re: Strong Bases
Are stronger acids/bases stronger because they have weaker intermolecular forces, and dissociate more completely?
- Sun Dec 02, 2018 11:40 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grades
- Replies: 10
- Views: 1162
Re: Final Grades
Hey so does anyone know how the grading in this class is done. Is the class curved or is there a specific rubric. I've been asking around but still can't seem to find out. Weekly Homework (7 pts per week) 70 pts Weekly Online Discussion (3 pts per week) 30 pts Three Discussion Section Tests (3 x 40...
- Mon Nov 26, 2018 2:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
- Replies: 37
- Views: 3306
- Mon Nov 26, 2018 2:06 pm
- Forum: Hybridization
- Topic: Questions in Chapter
- Replies: 5
- Views: 530
Re: Questions in Chapter
Dr. Lavelle said that we would go over naming on Wednesday. Does that mean that it will be on the test?
- Mon Nov 26, 2018 2:04 pm
- Forum: Hybridization
- Topic: Lone pair
- Replies: 4
- Views: 468
Re: Lone pair
Should we consider lone pair as sigma or pi bond when we do hybridization? For example if an central atom is linked with 3 atoms (sigma bond) and 1lone pair is it s1p3 or s1p2 hybridization? Thank you very much! I believe that the hybridization would be s1p3 because of the four regions of electron ...
- Sun Nov 18, 2018 10:44 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Square Planar
- Replies: 5
- Views: 574
Re: Square Planar
Are all square planar structures polar unless they have 4 of the same type of atom?
- Sun Nov 18, 2018 10:41 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing structures
- Replies: 8
- Views: 863
Re: Drawing structures
The solid wedge is the one in the foreground, and the dashed wedge represents the one in the back
- Sun Nov 18, 2018 10:40 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Week 7 Discussion Notes (3A, 3I, 3K)
- Replies: 4
- Views: 1135
Re: Week 7 Discussion Notes (3A, 3I, 3K)
Thank you Joyce
- Mon Nov 12, 2018 12:45 pm
- Forum: Dipole Moments
- Topic: Polarizability vs Polarizing Power
- Replies: 4
- Views: 384
Re: Polarizability vs Polarizing Power
not electronegative* just smaller cations
- Mon Nov 12, 2018 12:43 pm
- Forum: Dipole Moments
- Topic: Polarizability vs Polarizing Power
- Replies: 4
- Views: 384
Re: Polarizability vs Polarizing Power
In general larger atoms have greater polarizability and more electronegative atoms have greater polarizing power
- Mon Nov 12, 2018 12:39 pm
- Forum: Lewis Structures
- Topic: 7th edition 2E #5
- Replies: 2
- Views: 500
Re: 7th edition 2E #5
Adrian C 1D wrote:A)What is the shape of a ClO2+ ion?
B)What is the expected OCLO bond angle?
I know the bond angle would not be 180 degrees since the shape is not linear, but the answer says it is slightly less than 120 degrees. How did they arrive at this answer?
Because the molecule has lone pairs, it is bent
- Sun Nov 04, 2018 7:25 am
- Forum: Lewis Structures
- Topic: Lewis Structure
- Replies: 2
- Views: 293
Re: Lewis Structure
1. count total number of electrons
2. put element with lowest IE in the center
3. arrange electrons symmetrically around central atom
4. draw resonance if applicable
2. put element with lowest IE in the center
3. arrange electrons symmetrically around central atom
4. draw resonance if applicable
- Sun Nov 04, 2018 7:21 am
- Forum: Lewis Structures
- Topic: ground state configuration set up
- Replies: 3
- Views: 309
Re: ground state configuration set up
4s has a lower energy than 3d, so we fill that first. That's also why we generally take electrons from 4s first as well
- Sun Nov 04, 2018 7:19 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: s-block, p-block, d-block
- Replies: 3
- Views: 295
Re: s-block, p-block, d-block
Porus_Karwa_3C wrote:Hi just confirming for the midterm we'll only have to be responsible for the configuration of all of the s-block, all the p-block, and just the first row of the d-block?
My TA also mentioned that we should know/be able to draw the shapes of s, p, and d
- Tue Oct 30, 2018 10:34 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Can someone explain Te2-?
- Replies: 2
- Views: 3357
Re: Can someone explain Te2-?
This is from homework problem 3.21 c from the 6th edition. The shorthand used for Te 2- is [Xe], which comes after tellurium in the periodic table. When does an ion use the noble gas that comes before in its electron configuration and when does it use the noble gas which comes afterwards? Sorry, I ...
- Tue Oct 30, 2018 10:26 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: exceptions
- Replies: 6
- Views: 925
- Tue Oct 30, 2018 10:25 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: exceptions
- Replies: 6
- Views: 925
Re: exceptions
Arshia Ramesh 1G wrote:Why is it that chromium's electron configuration is [Ar]3d^5 4s^1? I get the [Ar] but why is it 3d^5 instead of 3d^4?
I believe that it is the element is more stable this way. The electrons are more evenly distributed because none are paired.
- Tue Oct 23, 2018 10:55 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: s, p, d, f subshells in multi-electron atoms
- Replies: 6
- Views: 618
Re: s, p, d, f subshells in multi-electron atoms
I'm confused about this statement from the 6th Edition Ch 2 #37b homework problem: Electrons in an s-orbital are more effective than those in other orbitals at shielding other electrons from the nuclear charge because an electron in an s-orbital can penetrate to the nucleus of the atom. Is this beca...
- Mon Oct 22, 2018 10:11 am
- Forum: Einstein Equation
- Topic: Rydberg Equation
- Replies: 2
- Views: 411
Re: Rydberg Equation
The second equation is to calculate energy of an electron at t a certain level. The Rydberg equation measures the frequency of energy released when electrons move between levels.
- Mon Oct 22, 2018 10:03 am
- Forum: Properties of Light
- Topic: Regions of Light
- Replies: 2
- Views: 257
Re: Regions of Light
I believe Dr. Lavelle said it wasn't necessary, but I'm not sure
- Mon Oct 22, 2018 10:02 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Symmetry in electron density distribution
- Replies: 3
- Views: 1710
Re: Symmetry in electron density distribution
Why are symmetry and nodal planes important in determining electrostatic interactions?
- Sun Oct 21, 2018 9:55 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 1E.5 7th Edition
- Replies: 2
- Views: 145
Re: 1E.5 7th Edition
I'm confused about this statement from the 6th edition in chapter 2: In other words, an s-electron is bound more tightly than a p-electron and has a slightly lower (more negative) energy Wouldn't an electron that is more tightly held have more positive energy because the nucleus "cancels out&qu...
- Tue Oct 16, 2018 11:57 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Indeterminacy in position
- Replies: 2
- Views: 288
Re: Indeterminacy in position
What steps did you take to solve the following problem (continuation of #18): Use the above uncertainty in velocity to calculate the electron's uncertainty in kinetic energy. Then calculate the uncertainty in kinetic energy per mole of electrons (that is, per mole of hydrogen atoms). Comment on your...
- Mon Oct 15, 2018 10:49 am
- Forum: Einstein Equation
- Topic: Numbers to memorize [ENDORSED]
- Replies: 37
- Views: 4569
Re: Numbers to memorize [ENDORSED]
Do you know how many significant figures we should use when solving problems, or should we just match the given information?
allisoncarr1i wrote:They are given on the exams but it might be helpful to familiarize yourself with some of the more frequently used constants just as a time saving technique.
- Mon Oct 15, 2018 10:47 am
- Forum: Properties of Light
- Topic: Test 2
- Replies: 17
- Views: 1445
Re: Test 2
So each outline corresponds with one test?
Sona Hakobyan 3J wrote:Everything regarding test 2 should be on outline 2 :)
- Mon Oct 15, 2018 9:53 am
- Forum: Properties of Light
- Topic: Colors and Frequency
- Replies: 14
- Views: 1742
Re: Colors and Frequency
I am wondering the same thing. Certain homework questions imply that we should memorize them, and they're not included in the constant worksheet on Dr. Lavelle's webpage Do we need to memorize which colors corresponds with which frequency/wavelength/energy of photons? For example, if given a wavelen...
- Sat Oct 13, 2018 5:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
- Replies: 135
- Views: 40817
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
Thank you so much!
Chem_Mod wrote:Week 2 worksheet for this week! We will go over quantum world material up to (not including) debroglie's wavelength.
- Thu Oct 11, 2018 1:06 am
- Forum: Photoelectric Effect
- Topic: post module assessment Q35B
- Replies: 2
- Views: 344
Re: post module assessment Q35B
I used the equation E=hv and v=c/lambda to find energy of the photon, but my answer for energy is 1.02*10^34 J. Is this correct? It seems like it's too small of a number but I can't find my mistake
- Wed Oct 10, 2018 10:47 am
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
- Replies: 135
- Views: 40817
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
Do you know if other UAs will be posting their worksheets? I know that it's best to go to as many peer learning sessions as possible, but I have some class time conflicts and would like to still get a lot of practice work done.
- Tue Oct 09, 2018 4:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 1 Study Plan
- Replies: 6
- Views: 660
Re: Test 1 Study Plan
Is test 2 solely going to be Quantum World material, or will it be cumulative? I'm trying not to fall behind in Chapter 1, but I also want to continue studying the review topics
- Fri Oct 05, 2018 10:04 am
- Forum: SI Units, Unit Conversions
- Topic: SI Units
- Replies: 7
- Views: 607
Re: SI Units
I believe that that it's better to air on the side of caution and always show units. On Lavelle's website, he included a link to an article about how important units are https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14A/14aflip.pdf Also, I find it much easier to solve problems (for n...
- Fri Oct 05, 2018 9:58 am
- Forum: SI Units, Unit Conversions
- Topic: formula units [ENDORSED]
- Replies: 69
- Views: 33686
Re: formula units [ENDORSED]
I'm also confused about formula units. Are they synonymous with "parts" within a salt? Why and when would a chemist use the word formula unit in place of the word atom? See my answers here: https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=26&t=32772&p=105307&sid=7e485d68778f...
- Fri Oct 05, 2018 9:54 am
- Forum: Significant Figures
- Topic: Zeros in sig figs
- Replies: 4
- Views: 616
Re: Zeros in sig figs
For significant figures:
-zeros between two significant figures are significant (8009 has 4 sig figs)
-zeros before a decimal point are significant (250. has 3 sig figs but 250 has 2)
-trailing zeros after a decimal point are significant (0.0080 has 2 sig figs but 0.008 has 1)
-zeros between two significant figures are significant (8009 has 4 sig figs)
-zeros before a decimal point are significant (250. has 3 sig figs but 250 has 2)
-trailing zeros after a decimal point are significant (0.0080 has 2 sig figs but 0.008 has 1)
- Sat Sep 29, 2018 6:16 pm
- Forum: SI Units, Unit Conversions
- Topic: How does grading for discussion posts work?
- Replies: 80
- Views: 10953
Re: How does grading for discussion posts work?
I assume that this week is the review given what my TA went over on Friday. However, I'm not positive and I plan to ask during office hours.
- Sat Sep 29, 2018 6:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Solutions Manual
- Replies: 9
- Views: 2010
Re: Solutions Manual
I purchased the 6th edition solutions manual, but it only has odd-numbered answers. Is there a way to check even answers, or am I looking in the wrong place?
- Sat Sep 29, 2018 6:05 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Question G21 [ENDORSED]
- Replies: 5
- Views: 458
Re: Question G21 [ENDORSED]
I tried G.21 part A and I got 4.58 * 10^-2 M for my answer. Do you think the masses of your compounds could be slightly off because you're using a different periodic table?