AgBr is being oxidized from 0 to +1, and subsequently Br- is being reduced from -1 to 0. This makes AgBr the anode and Br- the cathode, this is why they are included.
Hopefully that is the correct way to answer your question :)
Search found 44 matches
- Tue Mar 14, 2017 7:28 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell Diagram
- Replies: 3
- Views: 1042
- Tue Mar 14, 2017 7:22 pm
- Forum: Student Social/Study Group
- Topic: Strategies for studying for the final
- Replies: 9
- Views: 1619
Re: Strategies for studying for the final
That conceptual study guide sounds like a good idea! I may try that
- Thu Mar 09, 2017 4:19 pm
- Forum: Student Social/Study Group
- Topic: Midterm Review
- Replies: 1
- Views: 545
Re: Midterm Review
Which one? The Midterm Review Session or the Midterm answer review? I believe both should have been posted here on Chemistry Community.
- Thu Mar 09, 2017 4:17 pm
- Forum: *Cycloalkanes
- Topic: "iso" naming
- Replies: 4
- Views: 2688
Re: "iso" naming
Iso is not taken into alphabetical account, and it comes whenever there is a fork in the carbon substituent chain. For example: "isoethyl"
- Sun Mar 05, 2017 5:38 pm
- Forum: *Alkanes
- Topic: sec and tert
- Replies: 2
- Views: 605
Re: sec and tert
I don't believe we will be using the term "sec" quite yet. "Tert" is for when the carbons are perpendicularly arranged in a cross-shape, so you need a minimum of 4 carbons (Butyl).
- Fri Mar 03, 2017 12:43 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2978140
Re: Post All Chemistry Jokes Here
Thought this was Appropriate:
- Fri Mar 03, 2017 12:39 pm
- Forum: *Cycloalkanes
- Topic: Tert- Butyl
- Replies: 2
- Views: 533
Re: Tert- Butyl
I may be incorrect, however I think Iso- is used when the carbon are arranged in a linear chain. Thus Tert would be used when they are all perpendicular to each other, as seen in the Course Reader. I found this link to be very helpful, and you may as well :) http://web.chem.ucla.edu/~harding/IGOC/C/...
- Tue Feb 21, 2017 8:47 pm
- Forum: General Science Questions
- Topic: Significant Figures
- Replies: 1
- Views: 474
Re: Significant Figures
Significant figures should be computed at the end yo give the most accurate answer possible. If we take sig figs at each step of the problem our answer would have a heavy rounding bias.
- Tue Feb 21, 2017 8:46 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate Law Intermediate Slow before fast
- Replies: 2
- Views: 603
Re: Rate Law Intermediate Slow before fast
The intermediate can never be part of the rate law since it is consumed in the reaction. When this happens, substitute in for the intermediate in terms of its reactants.
- Tue Feb 14, 2017 9:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Half-reactions
- Replies: 1
- Views: 496
Re: Half-reactions
For this case water is not being included in the reaction, rather the half reaction is occurring in an acidic solution. These means we use water and H+ to balance our oxygen atoms.
- Tue Feb 14, 2017 11:37 am
- Forum: Calculating Work of Expansion
- Topic: 9.47
- Replies: 2
- Views: 777
Re: 9.47
The change in entropy is still the same, and you still would use ln in this case. Yet no work is done in free expansion, so the delta s of the surroundings is zero and q is zero. Only the internal entropy of the system increases in the irreversible process.
- Fri Feb 10, 2017 8:07 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electrolysis: Water 1/2 Rxn
- Replies: 1
- Views: 506
Re: Electrolysis: Water 1/2 Rxn
Well the first to you gave are the same reaction, except one is the oxidation and the other is the reduction reaction. As for the third reaction, that is for the formation of water from diatomic hydrogen and oxygen. Thus the question would have to explicitly state "water is formed from hydrogen...
- Fri Feb 10, 2017 7:54 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electrolysis
- Replies: 1
- Views: 490
Re: Electrolysis
Electrolysis is whenever an electron current is used to drive a reaction that may otherwise be non-spontaneous (+delta G). Redox reactions are thus often examples of electrolysis since they may not always be spontaneous and electrodes provide an electric current.
- Tue Feb 07, 2017 6:40 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Notation
- Replies: 2
- Views: 397
Re: Cell Diagram Notation
If I am correct yes the order does matter. This is based off whether it is the anode or cathode, in which it would go from the reactant being reduced or oxidized to the end result. Someone else feel free to add input.
- Fri Feb 03, 2017 4:47 pm
- Forum: Balancing Redox Reactions
- Topic: Electrodes
- Replies: 2
- Views: 533
Re: Electrodes
An electrode is always needed in an electro-chemical reaction. That is how electrons are transferred in the first place, a key component of any cell system.
- Fri Feb 03, 2017 4:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Extensive v Intensive
- Replies: 2
- Views: 598
Re: Extensive v Intensive
Intensive properties can be considered more useful in Chemical Applications because they are particularly helpful in the identification of chemical substances since they are not dependent on the amount of matter present in a system (as extensive properties are). For example, think of a colorful ruby...
- Tue Jan 31, 2017 10:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 1 Preparation Answers
- Replies: 130
- Views: 25166
Re: Quiz 1 Preparation Answers
BetcyGaspar_3C wrote:I do believe we use the equation deltaS=qrev/T,by plugging in 200J/(273+20) you will get the answer.
Thank you so much!
- Tue Jan 31, 2017 1:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 1 Preparation Answers
- Replies: 130
- Views: 25166
Re: Quiz 1 Preparation Answers
Could someone explain to me how to get #10 please? I am confused because we do not know the final temperature.
- Wed Jan 25, 2017 9:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz #1
- Replies: 1
- Views: 479
Re: Quiz #1
It depends on what the question asks for, it could be either kJ or J depending on what is given and what is most convent to use for the answer.
- Wed Jan 25, 2017 9:00 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Internal Energy Equation
- Replies: 1
- Views: 352
Re: Internal Energy Equation
I believe we would use it to find the specific heat (C) of a monatomic gas, however it is also used to prove that equation.
- Thu Jan 19, 2017 6:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Organic Chemistry Workbook
- Replies: 2
- Views: 652
Re: Organic Chemistry Workbook
If I am correct we will be using it in the second half of the quarter, Dr. Lavelle should tell us when we should start bringing it to class.
- Thu Jan 19, 2017 6:06 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Ch.8 #51
- Replies: 1
- Views: 358
Re: Ch.8 #51
In this case, energy is released when TNT is consumed. Thus it would be positive since the surrounding environment is getting an increase in energy. If the reaction was endothermic (e.g. bonds were formed) then the reaction energy would be - since energy is used up.
Hope that helps!
Hope that helps!
- Fri Jan 13, 2017 9:29 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Chapter 9 Question 31
- Replies: 1
- Views: 426
Re: Chapter 9 Question 31
If I am correct the 3/2 is simply given by the formula for the molar heat capacity of a monatomic ideal gas at constant volume. That is my opinion, but it amy not be correct so someone else's input would be helpful.
- Fri Jan 13, 2017 9:26 pm
- Forum: Calculating Work of Expansion
- Topic: Work Done
- Replies: 1
- Views: 457
Re: Work Done
Because the negative sign signifies that energy is released from the system. I think you were under the impression that this was akin to a number-line sort of scale, which is not the case here. -300kJ realized by a system is thus more work than -200kJ. Hope that helps, cheers.
- Thu Dec 01, 2016 8:53 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Table
- Replies: 3
- Views: 860
Re: ICE Table
The table is simply used to help determine the change in moles of reactants and products before and after a reaction takes place. Thus you would use it in acid base reactions, titrations, etc.
Hope that helps :)
Hope that helps :)
- Thu Dec 01, 2016 8:51 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: 3.17
- Replies: 1
- Views: 553
Re: 3.17
Assuming you mean Chapter 13, problem 17: The problem is asking you to generally predict the pH region (acidic or basic) where these buffers will be effective. Thus for part c, since KHP04 can give off a hydrogen it would act as an acid and thus be most effective as a buffer above pH 7., and Potassi...
- Thu Nov 24, 2016 2:27 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: using log
- Replies: 2
- Views: 539
Re: using log
Well log is short for logarithm, which is an essential way of expressing pH. pH describes the concentration of H+ ions in a solution, thus describing the strength of the solution (i.e. it's parts of Hydrogen or PH). Log is simply used to appreviate. Conversely there is pOH, as described in the cours...
- Thu Nov 24, 2016 2:23 pm
- Forum: Lewis Acids & Bases
- Topic: Determining which compound is stonger
- Replies: 2
- Views: 602
Re: Determining which compound is stonger
If I am correct, it is for the reason you cited. Because Chlorine is more electronegative, it holds onto its electrons. Thus it is more likely to give off an H+ ion, which would thus make it a stronger acid.
Hope that helps! :)
Hope that helps! :)
- Thu Nov 17, 2016 10:07 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydenates & Naming
- Replies: 2
- Views: 693
Re: Polydenates & Naming
For your first question, the easiest way is just to memorize the handy list Dr. Lavelle gave us. I guess you could draw out the Lewis structure to find the number of bonding sites in a ligand, but memorization is much easier (at least in my opinion). And for the second question, the prefixes (bi, tr...
- Thu Nov 17, 2016 10:02 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp and n
- Replies: 1
- Views: 1176
Re: Kp and n
You would omit solids and liquids, including only gases and aqueous compounds.
- Tue Nov 08, 2016 9:36 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ch 17 Q 33 d
- Replies: 1
- Views: 421
Re: Ch 17 Q 33 d
Oxalate is bidentate because each of the oxygen atoms serves as an area where oxalate can bind with other atoms. Since it has two oxygen atoms therefore it is bidentate.
- Mon Oct 31, 2016 9:28 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: When to use P sub x, P sub y and P sub z
- Replies: 1
- Views: 608
When to use P sub x, P sub y and P sub z
Hello all, I am confused as to when we should use P sub x, P sub y and P sub z in our electron configurations and when we could just write 2p5 or such. I believe I heard Professor Lavelle say that they are interchangeable and that the p sub is merely to help observe the sub-shells. Is this true, bec...
- Wed Oct 26, 2016 9:26 pm
- Forum: Octet Exceptions
- Topic: Half Full d^5 and Full d^10 Subshells
- Replies: 4
- Views: 1073
Re: Half Full d^5 and Full d^10 Subshells
The only exceptions we are expected to know are Cu and Cr, which in this case would be 4s1 3d5 and 4s1 3d10 respectively.
- Wed Oct 26, 2016 9:23 pm
- Forum: Trends in The Periodic Table
- Topic: D-block valence electrons? [ENDORSED]
- Replies: 4
- Views: 6505
Re: D-block valence electrons? [ENDORSED]
You take your valence electrons as everything after the noble gas configuration.
So for example, Zinc would have 12 valence electrons from the 3d10 4s2 that comes after [Ar]
Hope that answers your question
So for example, Zinc would have 12 valence electrons from the 3d10 4s2 that comes after [Ar]
Hope that answers your question
- Wed Oct 26, 2016 9:20 pm
- Forum: Trends in The Periodic Table
- Topic: Quiz 2 Question
- Replies: 1
- Views: 465
Re: Quiz 2 Question
It's the parts of chapter 2 that wasn't on quiz 1 and all of Chapter 3
- Wed Oct 19, 2016 8:24 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Question on Chapter 3, Question 19? [ENDORSED]
- Replies: 4
- Views: 1551
Re: Question on Chapter 3, Question 19? [ENDORSED]
3.19 part e) First take into consideration the actual electron configuration of Ni. When finding out the configuration take into account that the d subshell acts as a lower charge so should be in front of the configuration. So naturally, Ni configuration is [Ar]3d84s2 it is 3d8 because if you count...
- Tue Oct 18, 2016 10:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Question on Chapter 3, Question 19? [ENDORSED]
- Replies: 4
- Views: 1551
Question on Chapter 3, Question 19? [ENDORSED]
Hello all, Could someone please explain 3.19 part e It asks to give the "ground state electron configuration and number of unpaired electrons for Ni+2" The answer I got was 3d6 4s2 with no unpaired electrons but the answer the text gave was "3d8 and 2 unpaired electrons". Could s...
- Thu Oct 13, 2016 7:24 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Quiz 1 Fall 2015 #3 [ENDORSED]
- Replies: 3
- Views: 943
Re: Quiz 1 Fall 2015 #3 [ENDORSED]
Are we suppose to double the speed if its +/- to cover the entire range in all Heisenberg uncertainty problems then? Correct me if I am wrong, but on the Heisenberg problem in the practice quiz we turn in we do not double it because we want the minimum error and adding that uncertainty would rather...
- Thu Oct 13, 2016 7:22 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical equations too slow... any advice? [ENDORSED]
- Replies: 18
- Views: 3795
Re: Balancing Chemical equations too slow... any advice? [ENDORSED]
Personally I balance metals or other elements that are not H or O (such as C, N, Al, etc...) before I balance H and O. This is because most of the time there is some product such as H2 or H20 that i can use to help balance the equation at the end.
- Thu Oct 06, 2016 6:24 pm
- Forum: Student Social/Study Group
- Topic: Armenian Study Group
- Replies: 2
- Views: 825
Armenian Study Group
Glancing through the usernames, I noticed that I am certainly not the only Armenian student in Chemistry 14A.
Would any other Armenians care to form a study group? (All other nationalities are welcome too of course, I just want friends to study with! :) )
Ara Yazaryan
Would any other Armenians care to form a study group? (All other nationalities are welcome too of course, I just want friends to study with! :) )
Ara Yazaryan
- Thu Oct 06, 2016 6:20 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Collapse/Localize to a Nucleus [ENDORSED]
- Replies: 1
- Views: 564
Re: Collapse/Localize to a Nucleus [ENDORSED]
Well the purpose of this example is to show that ion fact electrons do not collapse to or are localized at the nucleus. Rather they exist in electron energy levels or "shells" around the nucleus, many times the diameter of the nucleus itself. The Indeterminacy principle shows us that the a...
- Wed Sep 28, 2016 5:58 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Post-Module Assessment #22-23
- Replies: 5
- Views: 7675
Re: Photoelectric Effect Post-Module Assessment #22-23
Yea you ALMOST finished the problem. What you found is the Energy of the PHOTON, but it is asking for the KINETIC energy. Therefore, because E(photon) - E(work function) = E (excess/kinetic energy)... 1.024998 x 10^-18 - 7.22 x 10^-19 (gotten from the previous problem) = 3.03 x 10^-19 J, which is B...
- Mon Sep 26, 2016 7:04 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Post-Module Assessment #22-23
- Replies: 5
- Views: 7675
Re: Photoelectric Effect Post-Module Assessment #22-23
Question Number Two To start off: Convert nanometers to meters since that is the unit we need to divide the speed of light by. 1 nm = 10^9 meters Thus 194 nm turns to 1.94 x 10^-7 m Then plug this into speed of light = (wavelength)(frequency) 3 x 10^8 = (1.94 x 10^-7)(frequency) Thus you get the fre...
- Mon Sep 26, 2016 6:41 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Post-Module Assessment #22-23
- Replies: 5
- Views: 7675
Re: Photoelectric Effect Post-Module Assessment #22-23
So for your first question.
Energy = (Frequency)(h)
h is Planck's constant which is 6.63 x 10^-34 J.s
So if you plug it into the formula you get:
(1.09x10^15)(6.63 x 10^-34) which thus gives you 7.2267x10^-19 J
:)
Energy = (Frequency)(h)
h is Planck's constant which is 6.63 x 10^-34 J.s
So if you plug it into the formula you get:
(1.09x10^15)(6.63 x 10^-34) which thus gives you 7.2267x10^-19 J
:)