Search found 31 matches
- Fri Mar 16, 2018 11:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: flipping half reactions
- Replies: 2
- Views: 562
flipping half reactions
How do we know which half reaction to flip?
- Fri Mar 16, 2018 11:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagram
- Replies: 4
- Views: 546
cell diagram
In a cell diagram, is the anode always on the left of the salt bridge and the cathode is always on the right side?
- Fri Mar 16, 2018 11:39 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Calculating Q in cell diagram
- Replies: 1
- Views: 277
Calculating Q in cell diagram
In some problems, Q is calculated as products/reactants while in other problems, it is calculated as anode/cathode. As a general rule, how do you calculate Q? Is it based on the type of problem?
- Tue Mar 13, 2018 9:42 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Adsorption
- Replies: 4
- Views: 690
Adsorption
Can somebody explain adsorption?
- Tue Mar 13, 2018 9:37 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: UV catalyst
- Replies: 3
- Views: 449
UV catalyst
In class we did an example of catalysts where UV light helped convert oxygen to ozone. Is UV light the catalyst in this example or is it another chemical species?
- Tue Mar 13, 2018 9:28 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Gas constants
- Replies: 2
- Views: 345
Re: Gas constants
Use the constant that make all the units that you don't want cancel.
- Wed Mar 07, 2018 12:08 am
- Forum: Second Order Reactions
- Topic: 15.35a
- Replies: 3
- Views: 580
Re: 15.35a
The book rounded the k value to 0.024L/molxs so that's why it's a slightly different answer.
- Wed Mar 07, 2018 12:05 am
- Forum: General Rate Laws
- Topic: Homework Problem 15.5
- Replies: 1
- Views: 203
Re: Homework Problem 15.5
You multiply by 3 because for every reaction, 3Oxygen is required so you have to multiply the overall rate .44 by the coefficient 3
- Tue Mar 06, 2018 11:59 pm
- Forum: First Order Reactions
- Topic: 15.37(B) homework
- Replies: 3
- Views: 491
15.37(B) homework
I couldn't figure out this question so I checked the solutions manual and it says eventually you get ln10/2.8x10^-3. I don't understand where the ln10 is coming from. Any help would be appreciated
- Tue Feb 27, 2018 8:53 pm
- Forum: General Rate Laws
- Topic: Negative 1/a
- Replies: 8
- Views: 1121
Negative 1/a
Why is there a "-" in -1/a in the differential rate law?
- Tue Feb 27, 2018 8:50 pm
- Forum: First Order Reactions
- Topic: Difference between 1st and 2nd order reactions
- Replies: 3
- Views: 21724
Difference between 1st and 2nd order reactions
What is the difference between 1st and 2nd order reactions besides the exponent?
- Tue Feb 27, 2018 8:42 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Hw 15.1 [ENDORSED]
- Replies: 7
- Views: 1114
Re: Hw 15.1 [ENDORSED]
Yes because for every 1 mol of N2 there's 3 moles of H2
- Wed Feb 21, 2018 12:07 am
- Forum: Balancing Redox Reactions
- Topic: redox agent
- Replies: 5
- Views: 696
redox agent
What's the difference between something that is being oxidized and an oxidizing agent? How can you tell which is which?
- Wed Feb 21, 2018 12:02 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: #14.23 finding n [ENDORSED]
- Replies: 3
- Views: 536
#14.23 finding n [ENDORSED]
When going through this problem, the solution manual says that n is 6 but I'm confused as to how we get that number. How do you find n for this question?
- Tue Feb 20, 2018 11:58 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: platinum in cell diagram
- Replies: 3
- Views: 383
platinum in cell diagram
What's the purpose of using platinum in a cell diagram?
- Tue Feb 13, 2018 8:58 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: DeltaG spontaneous
- Replies: 1
- Views: 288
DeltaG spontaneous
I know that a reaction with a negative deltaG is spontaneous, but what exactly does it mean to be spontaneous?
- Tue Feb 13, 2018 8:47 pm
- Forum: Calculating Work of Expansion
- Topic: W=-P(deltaV) sign
- Replies: 3
- Views: 459
Re: W=-P(deltaT) sign
Sorry it should be a V not a T
- Tue Feb 13, 2018 8:45 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: (DeltaU)=q+w Isothermal
- Replies: 2
- Views: 377
(DeltaU)=q+w Isothermal
I know that when there is no heat flow, DeltaU=w, but are there any other circumstances when an equation can be changed like that because it is isothermal or something that has a constant volume?
- Tue Feb 13, 2018 8:37 pm
- Forum: Calculating Work of Expansion
- Topic: W=-P(deltaV) sign
- Replies: 3
- Views: 459
W=-P(deltaV) sign
Why is there a negative in front of V? I know it has something to do with work done on the system/surroundings but I am confused which sign goes with what.
- Mon Feb 05, 2018 6:03 pm
- Forum: Balancing Redox Reactions
- Topic: Salt Bridges
- Replies: 14
- Views: 1363
Re: Salt Bridges
A salt bridge allows for ion transfer between the two solutions, and this allows for the two solutions to stay neutral.
- Mon Feb 05, 2018 5:57 pm
- Forum: Balancing Redox Reactions
- Topic: acronym for reduction
- Replies: 5
- Views: 2431
acronym for reduction
I know that "LEO" is an acronym for oxidation reactions, but is there an acronym for reduction reactions?
- Mon Feb 05, 2018 5:49 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Vibrationally Active
- Replies: 1
- Views: 441
Re: Vibrationally Active
The more it vibrates, the more chance of molecules hitting into eachother, and therefore the higher the entropy is.
- Mon Jan 29, 2018 4:32 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: formula for standard entropy
- Replies: 5
- Views: 790
formula for standard entropy
Is the formula for the standard entropy the same as the formula for then standard enthalpy? They seem very similar but I just want to make sure
- Mon Jan 29, 2018 4:28 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Entropy Change factors
- Replies: 6
- Views: 791
Re: Entropy Change factors
A more complex molecule would have a higher delta S because a more complex molecule has more possible vibrations and motions making the entropy greater.
- Mon Jan 29, 2018 4:26 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: sign of entropy
- Replies: 11
- Views: 1688
sign of entropy
How do I know whether the entropy has a "+" or a "-"?
- Sun Jan 21, 2018 9:09 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: work definition
- Replies: 5
- Views: 720
work definition
What is a simple definition for work? I keep getting it confused with heat
- Sun Jan 21, 2018 9:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 3 Test Topic is endorsed
- Replies: 37
- Views: 4934
Re: Week 3 Test Topic is endorsed
Are there any formulas that we need to memorize?
- Sun Jan 21, 2018 8:57 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated vs Closed system
- Replies: 3
- Views: 4158
Isolated vs Closed system
What is the difference between an isolated and a closed system?
- Wed Jan 10, 2018 6:35 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why can state properties be added?
- Replies: 11
- Views: 1306
Why can state properties be added?
I understand the definition of state properties but I am a little confused as to why they can be added and subtracted. Any help would be greatly appreciated!
- Wed Jan 10, 2018 6:01 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endo and Exothermic Ways to Remember
- Replies: 28
- Views: 11694
Re: Endo and Exothermic Ways to Remember
A quick way I use is "into endo" and "exhale exo". Heat goes into the system during an endothermic reaction and heat is exhaled during a exothermic reaction.
- Wed Jan 10, 2018 5:48 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Specific heat of water
- Replies: 3
- Views: 349
Specific heat of water
Why does the liquid form of water have a higher specific heat than the solid and gas versions?