Search found 12 matches

Sun Feb 12, 2017 4:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Half reactions for galvanic cells
Replies: 1
Views: 207

Re: Half reactions for galvanic cells

I think that, when writing half-reactions, the order of the elements doesnt matter. Only the location of the electrons or of the reduced/oxidized element (ie reactants or products) matters. Also, electrons will only be on the reactants side of a half-reaction if the metal is being reduced.
Sun Feb 12, 2017 4:25 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Methods of finding K
Replies: 1
Views: 258

Re: Methods of finding K

Yes, but each equation has different values that must be known. Thus both equations are not useful in every situation.
Sun Feb 12, 2017 4:23 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Course reader example pg. 7 electrochemistry
Replies: 4
Views: 550

Re: Course reader example pg. 7 electrochemistry

I think the laminated sheet has a typo. There should be a decimal point before the last three, otherwise the use of the comma doesn't make sense. Faraday's Constant is 96,485.3 C/mol.
Tue Jan 31, 2017 9:09 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Sig Figs
Replies: 3
Views: 534

Re: Sig Figs

I'd def go least. Conventions dictate that the least accurately known number be reflected in the accuracy of the answer.
Mon Jan 30, 2017 7:56 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible and Irreversible entropy equations
Replies: 1
Views: 296

Re: Reversible and Irreversible entropy equations

I think thats how things work, although i will admit irreversible reactions don't seem to come up a lot in the textbook.
Mon Jan 30, 2017 7:50 pm
Forum: Balancing Redox Reactions
Topic: Question regarding: "E° + Value means reduction is spontaneous"
Replies: 3
Views: 556

Re: Question regarding: "E° + Value means reduction is spontaneous"

I think its "E positive value," not E plus value.
Mon Jan 30, 2017 7:49 pm
Forum: Phase Changes & Related Calculations
Topic: Practice Quiz 1 #9
Replies: 2
Views: 345

Re: Practice Quiz 1 #9

Because the piston expands while the gas is being heated, I believe. Its not stated explicitly, but I think thats the right answer.
Thu Jan 26, 2017 2:30 pm
Forum: Phase Changes & Related Calculations
Topic: Homework Question 8.67
Replies: 3
Views: 404

Re: Homework Question 8.67

Worst comes the worst we may have to calculate deltaH(rxn) from a table of bond destruction and creation energies.
Thu Jan 26, 2017 2:26 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.33 part a
Replies: 1
Views: 206

Re: 9.33 part a

From what I understand, gas is the most random state of matter, so going from a gaseous state to an aqueous state will result in a decrease in entropy.
Thu Jan 26, 2017 2:22 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Example of isolated System
Replies: 4
Views: 5915

Re: Example of isolated System

I think its actually pretty hard to have a completely isolated system, as there will always be some amount of heat or other energy transfer. But I second the bomb calorimeter and the thermos. Another good one might be a human body in an acclimated dry suit...
Mon Jan 23, 2017 11:05 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Caliometry
Replies: 1
Views: 288

Re: Caliometry

To my understanding, caliometry works like this: a known amount of substance (known weight and therefore known moles) is enclosed in an isolated chamber surrounded in water of a known temperature and volume. An electrical charge is applied and the substance burned. Once all of the substance has been...
Sun Jan 15, 2017 2:33 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Ch 8. Q.1 [ENDORSED]
Replies: 2
Views: 445

Re: Ch 8. Q.1[ENDORSED]

The way I thought about this one has to do with defining the system. I defined the system as the combustion chamber and the surroundings as everything else. Thus, both matter and energy are able to enter and leave the system at will, because a gasoline or diesel engine requires an intake of O2 and a...