Search found 16 matches

by 204301116
Fri Mar 13, 2015 10:50 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Q concentrations
Replies: 3
Views: 502

Re: Q concentrations

Thank you. Here is a picture of the full questions. It is page 159 in the book "Decades of midterms and finals" from 2005-2014. Thanks!
by 204301116
Thu Mar 12, 2015 2:52 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Delta H of combustion
Replies: 1
Views: 694

Delta H of combustion

Can someone please explain this to me? I understand that for methane the coefficient of CO2 is 1 and for ethanol liquid and octane it is 2, but how did they get the answer for octane? Thanks
by 204301116
Thu Mar 12, 2015 2:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Q concentrations
Replies: 3
Views: 502

Q concentrations

In this question, how does Q=1/(1x10^-6) ?
Q should be= (H)^2/(H2)(Cu2+)
do the (h)^2/(H2) cancel out somehow?
by 204301116
Thu Mar 12, 2015 2:33 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: substituting intermediates in rate laws
Replies: 3
Views: 837

substituting intermediates in rate laws

In question 4B of the 2014 final, why does C have to be substituted for in the equation? I know that you have to substitute for E because it is an intermediate. But since C doesn't get canceled out, I thought it is not an intermediate? Thanks
by 204301116
Thu Mar 12, 2015 12:43 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Activation energy vs. delta G
Replies: 1
Views: 2685

Activation energy vs. delta G

For a reaction profile with potential energy as the Y-axis, the difference between the reactants and the transition state is the activation energy. I thought that if a reaction profile has Delta G for the Y-axis, then the difference between reactants and products will be the delta G with the 2 pluse...
by 204301116
Mon Feb 09, 2015 10:11 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: reverse reactions
Replies: 1
Views: 517

reverse reactions

How do you know which half reaction to reverse? Is it true that for a galvanic cell you always make the smaller number negative, because you always want a positive E? What if the type of cell is not specified? For example, in question 8 on the 2014 midterm, the bigger number is reversed, making E ne...
by 204301116
Sun Feb 08, 2015 7:32 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Calculating Q
Replies: 2
Views: 475

Calculating Q

Is Q always the concentration of the anode over the concentration of the cathode? or does it depend on the situation?
by 204301116
Sun Feb 08, 2015 2:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Order of reactants in cell diagrams
Replies: 1
Views: 356

Order of reactants in cell diagrams

If there is more than one reactant, does it matter what order we put them in? For example, chapter 13 question 21 part a, does it matter if we out the NO3- first or the H+ first? They are both reactants in the cathode. Also, in part C, the half reaction is Cr2O7 (2-) + 14H+ +6e- --> 2Cr(3+) +7H2O an...
by 204301116
Sun Feb 08, 2015 1:58 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Order in cell diagram
Replies: 1
Views: 285

Order in cell diagram

In part c in question 13 of chapter 13, the Cl- is placed before the Cl2, but the half reaction is Cl2 +2e- --> 2Cl-
I thought that in the cell diagram it would be Cl2 before Cl- since that is the order of the reaction, why is it switched?
by 204301116
Fri Feb 06, 2015 1:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Pt in cell diagrams
Replies: 1
Views: 383

Pt in cell diagrams

Can someone please clarify when we put Pt in cell diagrams? How do we know if it goes on one side or both sides? Thanks
by 204301116
Fri Dec 12, 2014 12:51 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Ionization energy
Replies: 1
Views: 410

Ionization energy

Why is does F2 + have higher ionization energy than F2 2- ?
by 204301116
Wed Dec 10, 2014 12:19 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: 2 different elements for MO
Replies: 1
Views: 358

2 different elements for MO

For a molecular orbital problem with 2 different elements, how do you know which energy-level diagram to use? How do you know whether to use the diagram for Li2-N2 or the one for O2-F2?
by 204301116
Wed Dec 10, 2014 12:08 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Br 2+
Replies: 7
Views: 2546

Br 2+

In one of the practice finals it says that Br 2+ is diamagnetic. Can someone please explain this to me? I thought it should be paramagnetic with 2 unpaired electrons.
by 204301116
Wed Dec 10, 2014 12:04 am
Forum: Naming
Topic: bis and tris
Replies: 3
Views: 4847

bis and tris

How do you know when to use bis and tris as opposed to di, tri, tetra.. ?

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