Search found 38 matches
- Thu Mar 16, 2017 11:33 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Constant Volume and Constant Pressure
- Replies: 3
- Views: 807
Constant Volume and Constant Pressure
Homework problem 9.7 that wants us to find the entropy change of 1 mol of ideal gas with a temperature change under constant pressure and constant volume. For the final, would we need to know that constant pressure is (5/2)R and that constant volume is (3/2)R? Also, for that same problem, how can so...
- Sun Mar 12, 2017 9:04 pm
- Forum: *Alcohols
- Topic: C and functional groups
- Replies: 2
- Views: 685
C and functional groups
Can functional groups share a carbon?
- Wed Mar 01, 2017 2:57 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Ch4 Admin. Question
- Replies: 1
- Views: 455
Homework Ch4 Admin. Question
For the Homework from Ch 4, are we only suppose to do the odd-numbered problems? If we are also recommended to do the even-numbered problems, is there a way to access the solutions to those?
- Thu Feb 23, 2017 8:33 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate Law and Intermediates
- Replies: 1
- Views: 547
Rate Law and Intermediates
Is a rate law allowed to have an intermediate concentration? or do we always have to solve with K to find the substitute for the intermediate? (such an the pre-equilibrium example in the course reader)
- Wed Feb 22, 2017 4:10 pm
- Forum: General Rate Laws
- Topic: Quiz Equations
- Replies: 1
- Views: 413
Quiz Equations
For our quiz this week, will we be given the equations for zero, first, and second order reactions? Will we be given these equations, but with each just not identified as to which equation it is? or will we not be given any equations at all on our 'givens' note sheet?
- Thu Feb 16, 2017 5:10 pm
- Forum: General Rate Laws
- Topic: General Rate Question
- Replies: 2
- Views: 663
General Rate Question
When solving homework problems, are we only suppose to be finding rates in (mol)/(L*s) or are we allowed to also express it in (mmol)/(L*s) depending on the units given in the problem? More specifically, on a quiz or test, will we be marked off for using mmol instead of mol?
- Mon Feb 13, 2017 4:37 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: H2O in Galvanic Cell Diagram
- Replies: 1
- Views: 1504
H2O in Galvanic Cell Diagram
When is water included in the Galvanic Cell Diagram? There have been a few problems in the homework in which water is involved in the reaction, but not included in the call diagram. (problem 14.11d, problem 14.15b, problem 14.23 a and c)
- Sun Feb 12, 2017 11:22 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: homework 14.35
- Replies: 2
- Views: 568
homework 14.35
Can anyone confirm that the solutions manual for 14.35 part b) is incorrect? The solutions wrote one of the half reactions as In^3+ (aq) + 2 e- ----> In^2+ (aq). The coefficient of the electron is obviously wrong as +3 - 2 does not equal +2. From my calculations considering n = 1, I obtained K = 1.0...
- Thu Feb 09, 2017 9:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 3
- Views: 749
Re: Cell Diagrams
Very helpful! Thanks!
- Thu Feb 09, 2017 10:01 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 3
- Views: 749
Cell Diagrams
I understand that the anode is on the right side of the cell diagram, and that the cathode is on the left side of the cell diagram, but does the order of the molecules within the anode or cathode matter for the diagram?
- Wed Feb 08, 2017 11:52 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Homework 14.11
- Replies: 1
- Views: 475
Homework 14.11
The solution states that Ni^2+ (aq) + 2e ---> Ni (s) has E(anode) = -0.23 V. The solution proceeds to flip the reaction so that the reaction is Ni (s) ----> Ni^2+ (aq) + 2e but does not switch the sign of the E(anode) to +0.23V. Aren't we always suppose to change the sign of the voltage when we reve...
- Thu Feb 02, 2017 9:20 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Writing Balanced Equations
- Replies: 1
- Views: 537
Writing Balanced Equations
When writing balanced equations in order to calculate Gibbs free energy from the Gibbs free energy of formation of the products and reactants, how do we know whether to use full integers to balance equations or fractions. For example, on problem 9.59, 2 Fe3O4 (s) + O2 (g) ---> 3 Fe2O3 was balanced t...
- Sat Jan 28, 2017 2:59 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Homework 9.51
- Replies: 1
- Views: 411
Homework 9.51
9.51 asks, why are so many exothermic reactions spontaneous? the answer gives the equation deltaG = deltaH - TdeltaS and says that exothermic reactions tend to be spontaneous because the result in an increase in the entropy of the surroundings. My question is, does the deltaS in the equation represe...
- Fri Jan 27, 2017 11:47 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy from Mass
- Replies: 1
- Views: 576
Entropy from Mass
Homework problem 9.27.
Which has great entropy, HBr(g) or HF(g). The answer is HBr, and the solutions says that it is because Br is more massive and contains more elementary particles than F. What elementary particles is it talking about?
Which has great entropy, HBr(g) or HF(g). The answer is HBr, and the solutions says that it is because Br is more massive and contains more elementary particles than F. What elementary particles is it talking about?
- Fri Jan 27, 2017 11:40 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Homework Problem 9.25
- Replies: 1
- Views: 458
Homework Problem 9.25
My calculator will not compute ln(6^(6.02*10^23)) listed in the solution. It replies back with "overflow" anytime I enter this value. Will we have to worry about this for the quiz?
- Fri Jan 27, 2017 10:20 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Homework Problem 9.13
- Replies: 1
- Views: 564
Homework Problem 9.13
My questions pertains to Ch 9 Problem 13: During the test of an internal combustion engine, 3L or nitrogen gas at 18.5 degrees C was compressed suddenly (and irreversibly) to 0.5L by driving in a piston. In the process, the temperature of the gas increased to 28.1 degrees C. Assume ideal behavior. w...
- Fri Jan 27, 2017 9:22 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Changing Pressure
- Replies: 1
- Views: 463
Changing Pressure
What equation would we use when calculating entropy and enthalpy when pressure is changing?
- Mon Jan 23, 2017 4:57 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Memorize Values for Quiz?
- Replies: 1
- Views: 834
Memorize Values for Quiz?
Will we have to have the values of the enthalpy of vaporization or fusion or the specific heat capacities of different states of water memorized for the quiz or will they be given?
- Sun Jan 22, 2017 7:57 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: The Value of R
- Replies: 2
- Views: 681
The Value of R
what is a good rule of thumb for knowing which value of R we should use? (technically same value but just in different units)
- Sun Jan 22, 2017 7:33 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Molar Heat Capacities
- Replies: 1
- Views: 500
Molar Heat Capacities
For our quiz or midterm, will we need to have memorized the equations for molar heat capacity at constant volume and also at constant pressure? As in the 3/2R, 5/2R, 3R etc.?
- Thu Jan 12, 2017 3:17 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Problem 8.49
- Replies: 4
- Views: 745
Problem 8.49
I'm having some trouble understanding homework problem 8.49. It asks for the change in internal energy for the reaction of 1 mol of OF2 (g). Why wouldn't the change in internal energy just be the delta H given? Why do we have to take the work (-PdeltaV) into account? What work is being done? Wouldn'...
- Wed Jan 11, 2017 3:38 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bonding Enthalpies
- Replies: 2
- Views: 526
Bonding Enthalpies
For some clarification of the example in the course reader about enthalpies of bonds breaking (involving C-C, C-H, and C-Br bonds), is it correct that we have to account for the formation of the C-C single bond because the C=C breaks completely before it forms a single bond, rather than just jumping...
- Tue Jan 10, 2017 3:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Workbook
- Replies: 2
- Views: 634
Workbook
Were we suppose to receive a workbook for 14B from the course reader store?
- Sun Dec 04, 2016 8:43 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Final [ENDORSED]
- Replies: 6
- Views: 1745
Chem Final [ENDORSED]
When can we expect to receive our grades for the course? Thanks for a great quarter! :)
- Thu Nov 17, 2016 4:49 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3457731
Re: Post All Chemistry Jokes Here
lovin all these chem jokes (click jump to post if you can't see the image)
- Tue Nov 01, 2016 9:35 pm
- Forum: Lewis Structures
- Topic: Homework 3.95
- Replies: 1
- Views: 393
Homework 3.95
How do we know that the formal charge of CH2 with one bond and one electron pair is -1?
- Sun Oct 30, 2016 4:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Homework 4.25 [ENDORSED]
- Replies: 1
- Views: 674
Homework 4.25 [ENDORSED]
When drawing CH2Cl2, how does one know to place the H molecules next to each other and Cl molecules next to each other, rather than drawing them across from each other so that the molecule is non polar?
- Sun Oct 30, 2016 4:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lewis structure and molecular shapes [ENDORSED]
- Replies: 1
- Views: 557
Lewis structure and molecular shapes [ENDORSED]
How do you know when to write the Lewis structure like the one on the left versus the one on the right? (Attached picture)
- Sun Oct 30, 2016 3:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw angles
- Replies: 1
- Views: 534
Seesaw angles
For a molecule that has a seesaw shape because of one lone pair of electrons, wouldn't the bond angles be slightly less than 90 degrees and slightly less than 180 degrees because of the repulsion from the lone pair?
- Sun Oct 30, 2016 2:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: ICL3 bond angles
- Replies: 1
- Views: 4537
ICL3 bond angles
Homework question 4.9 asks for the shape of ICL3 and the ClICl bond angle.
ICL3 is T-shaped, and the solutions manual only lists the slightly less than 90 degree angle, but shouldn't we also note that there's a slightly less than 180 degree angle? Will we have to note both angles on the midterm?
ICL3 is T-shaped, and the solutions manual only lists the slightly less than 90 degree angle, but shouldn't we also note that there's a slightly less than 180 degree angle? Will we have to note both angles on the midterm?
- Wed Oct 26, 2016 6:08 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations Exceptions?
- Replies: 3
- Views: 1562
Electron Configurations Exceptions?
The solutions manual for electron configuration problems does not seem take into account the exceptions to electron configuration orbital patterns (unless I'm mistaken).
Should we not take into account the exceptions on the quiz when writing electron configurations on the quiz?
Should we not take into account the exceptions on the quiz when writing electron configurations on the quiz?
- Tue Oct 25, 2016 7:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz Info
- Replies: 2
- Views: 679
Quiz Info
I missed the first 15 min of class on Monday. Were there any announcements regarding the quiz or other important info that I missed?
Thanks!
Thanks!
- Fri Oct 21, 2016 12:11 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3457731
Re: Post All Chemistry Jokes Here
What is the chemical formula for coffee?
CoFe2
CoFe2
- Tue Oct 11, 2016 10:32 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Pre Assessment Questions
- Replies: 2
- Views: 648
Pre Assessment Questions
Pre assessment question from the Heisenberg Uncertainty module: The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1 % of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertain...
- Mon Oct 10, 2016 9:42 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3457731
Re: Post All Chemistry Jokes Here
What did iodine say while spying on copper?
I see you.
I see you.
- Thu Oct 06, 2016 4:32 pm
- Forum: Balancing Chemical Reactions
- Topic: Naming Compounds
- Replies: 2
- Views: 889
Naming Compounds
anyone have a good resource for memorizing the names and charges of compounds?
- Thu Sep 29, 2016 6:26 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Other Fundamentals
- Replies: 1
- Views: 296
Other Fundamentals
Will we have quiz or test questions from the other fundamental sections not covered by Chem Refreshers or Audio Visual Topics (aka Fundamentals A B C D I J K), or should we just focus in on the fundamentals that Dr. Lavelle emphasizes (E F G H L M)?
- Tue Sep 27, 2016 10:01 am
- Forum: Administrative Questions and Class Announcements
- Topic: Undergraduate Assistants
- Replies: 1
- Views: 1545
Undergraduate Assistants
Do UAs have specific office hours or are they only available through email?