## Search found 22 matches

Sun Mar 13, 2016 6:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 2016 Final exam
Replies: 1
Views: 253

### 2016 Final exam

On the final exam, on of the questions asked for cel potential but all it gave was the half reactions and the standard cell potentials. How are we supposed to calculate the cell potential if we weren't given the concentrations to find Q? Or by cell potential did they mean standard cell potential?
Sun Mar 13, 2016 2:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Free expansion
Replies: 1
Views: 237

### Free expansion

In free expansion, is q,w,and h equal to 0? What else applies under free expansion ?
Sun Mar 06, 2016 7:41 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ethane vs Ethene
Replies: 1
Views: 335

### Ethane vs Ethene

On one of the final exams, it says that ethane has a higher heat capacity than ethene? I don't understand why. Could someone explain to me why that is ? Thank you.
Fri Mar 04, 2016 10:46 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Energy of Transitional States
Replies: 2
Views: 487

### Re: Energy of Transitional States

A larger delta G^# means that the step takes more energy to happen. So yes, it is less likely to happen if compared to a lower delta G^#
Fri Mar 04, 2016 10:44 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Stability
Replies: 2
Views: 459

### Re: Stability

Thermodynamically stable means that delta G is negative. So when delta G <0 the products are thermodynamically stable. If Delta G>0 the reactants are thermodynamically more stable.
Wed Feb 24, 2016 2:56 pm
Forum: *Alkanes
Topic: Double or Triple Bond as substituents
Replies: 1
Views: 212

### Double or Triple Bond as substituents

Will we ever have to name or draw a compound that has a substituent with a double bond? I know that substituents end in -yl but would having a double or triple bond make the substituent -yne or -ene and without the -yl suffix?
Wed Feb 24, 2016 2:52 pm
Forum: *Alkanes
Topic: Double and Triple Bonds
Replies: 1
Views: 375

### Double and Triple Bonds

If a molecule has a double and a triple bond, Would that be alkene or alkyne? Or does one overpower the other. I guess what I'm asking is, How would a molecule like this be named.
Sat Feb 20, 2016 6:56 pm
Forum: General Rate Laws
Topic: Units?
Replies: 3
Views: 576

### Re: Units?

The Units for K will always be representative of the order of the reaction (m/s, 1/s, 1/ms, 1/m2s, etc) . The units of the reaction rate will always be Molarity/Seconds (m/s)
Sat Feb 20, 2016 6:53 pm
Forum: General Rate Laws
Topic: "a"
Replies: 2
Views: 419

### Re: "a"

The a is the coefficient.
Sat Feb 20, 2016 6:50 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Steady State vs Pre Equlibrium
Replies: 1
Views: 414

### Steady State vs Pre Equlibrium

In the course reader, it says that pre equilibrium approach is easier than steady state but less flexible. What does that mean? Also, What is steady state approach. I understand pre equilibrium but what is steady state?
Sun Feb 07, 2016 8:27 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Delta G
Replies: 1
Views: 336

### Delta G

Is it arbitrary for which delta G equation you can use? delta G=-nFE
or Delta G=-RTlnK ?

Are we only supposed to use each on certain circumstances?
Wed Jan 27, 2016 8:00 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Constrictions in Space
Replies: 1
Views: 283

### Constrictions in Space

So I am not sure where I read a problem like this but it said that the reaction was in space. What type of constrictions does that put on the reaction. If isothermal is equivalent to delta U=0 then what is space equivalent to?
Sat Jan 23, 2016 12:21 am
Forum: Calculating Work of Expansion
Topic: Work
Replies: 1
Views: 241

### Re: Work

If volume is constant then work is 0. This is because w=-P(change in)V and if there is no change in volume, then w=p(0), thus making work = 0
Mon Jan 11, 2016 1:17 am
Forum: Phase Changes & Related Calculations
Topic: Homework
Replies: 2
Views: 412

### Re: Homework

Professor Lavelle usually bullet points the name of the topic the he is discussing at the top of the page. If that doesn't help, You can find the topics related to his lectures by taking important key words from the course reader lecture and finding the page number where they discuss such topics in ...
Mon Jan 11, 2016 1:13 am
Forum: Phase Changes & Related Calculations
Topic: Thermochemistry related to 14A
Replies: 1
Views: 253

### Thermochemistry related to 14A

So I am not familiar with organic and thermochemistry but I am familiar with the material Professor Lavelle taught in 14A. Does 14A have to do a lot with the material in 14B ? Is 14B material separate from things such as the Rydberg equation, Photons, Molecular orbital, etc?
Sun Nov 29, 2015 11:35 pm
Forum: Lewis Acids & Bases
Topic: determining lewis acids and bases
Replies: 2
Views: 448

### Re: determining lewis acids and bases

if it helps you remember then you can but i've heard from a lot of TA's that you should memorize them. There's many trends that makes it easy to determine which are acids and bases and which are weak and strong (Aka groups 1 and 2, and the COOH and more)
Fri Nov 27, 2015 11:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium Problems
Replies: 1
Views: 438

### Chemical Equilibrium Problems

This is my video Submission. This is a problem from quiz 3 of the workbook on chemical equilibrium. Please comment if you would like.
Thank You,
Odalis Trasvina
Sun Nov 22, 2015 9:57 pm
Forum: Ideal Gases
Topic: When is K small enough to make the assumption
Replies: 2
Views: 616

### When is K small enough to make the assumption

So i've been hearing different things about when to make the assumption about K and when it is small enough to be disregarded in the quadratic steps of finding equilibrium. Is it when K is 10^-4 and less or 10^-5 and less.
Thu Nov 12, 2015 3:03 pm
Forum: Ideal Gases
Topic: Ratios and Change
Replies: 1
Views: 324

### Ratios and Change

If the concentration of a reactant and product do not change with time, will their ratio change with time?
Thu Oct 29, 2015 6:03 pm
Forum: Hybridization
Topic: Hybridization
Replies: 3
Views: 464

### Re: Hybridization

So if an element in a molecule has, for example, four bonds attached to it, then its hybridization would be sp^3. This is because sp3 adds up to four bonds. one s and three p's (adding up to four) For any case, You can think of it as s having only one orbital, p having 3 orbitals and d having 5 orbi...
Sun Oct 18, 2015 1:54 pm
Forum: Quantum Numbers and The H-Atom
Topic: Orbital occupation exceptions
Replies: 1
Views: 327

### Orbital occupation exceptions

2.85 In the heavier transition-metal elements, especially the lanthanoids and actinoids, there are numerous exceptions to the regular order of orbital occupation predicted by the building- up principle. Suggest why more exceptions would be noted for these elements.
Thu Oct 01, 2015 5:44 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Finding number of atoms, formula units and moles
Replies: 4
Views: 21674

### Finding number of atoms, formula units and moles

Epsom salts consist of magnesium sulfate heptahydrate. Write its formula. (a) How many atoms of oxygen are in 5.15 g of Epsom salts? (b) How many formula units of the compound are present in 5.15 g? (c) How many moles of water molecules are in 5.15 g of Epsom salts?