## 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: 246

### 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: 262

### 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: 136

### 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
Replies: 4
Views: 280

Tue Mar 13, 2018 9:37 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: UV catalyst
Replies: 3
Views: 240

### 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: 162

### 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: 326

### 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: 77

### 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: 221

### 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: 493

### 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: 14011

### 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: 472

### 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: 303

### 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: 224

### #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: 127

### 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: 131

### 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: 219

### 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: 180

### (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: 219

### 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: 522

### 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: 518

### 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: 250

### 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: 387

### 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: 399

### 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: 671

### 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: 297

### 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: 2932

### 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: 849

### 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: 684

### 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: 5645

### 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: 233

### Specific heat of water

Why does the liquid form of water have a higher specific heat than the solid and gas versions?