Search found 30 matches
- Sat Mar 16, 2019 1:11 pm
- Forum: Balancing Redox Reactions
- Topic: How to tell if its in acidic or basic
- Replies: 6
- Views: 702
Re: How to tell if its in acidic or basic
It's usually acidic unless otherwise stated
- Tue Mar 12, 2019 10:33 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3881492
Re: Post All Chemistry Jokes Here
I would tell another chemistry joke
...but all the good ones Argon.
...but all the good ones Argon.
- Tue Mar 12, 2019 10:33 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3881492
Re: Post All Chemistry Jokes Here
Why does hamburger have less energy than steak?
It's the ground state.
It's the ground state.
- Tue Mar 12, 2019 10:29 pm
- Forum: General Rate Laws
- Topic: Unique rate law
- Replies: 1
- Views: 278
Unique rate law
In what situation would we use the rate of formation or the unique rate law? How will we be able to tell?
- Tue Mar 12, 2019 10:26 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sig Figs
- Replies: 9
- Views: 1175
Sig Figs
I heard from my TA that sig figs will be graded. Has anyone heard something similar or different?
- Tue Mar 12, 2019 10:23 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3881492
Re: Post All Chemistry Jokes Here
What's the difference between chemistry jokes and physics jokes?
Chemistry jokes can be funny periodically, but physics jokes have more potential.
Chemistry jokes can be funny periodically, but physics jokes have more potential.
- Tue Mar 12, 2019 9:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test #2 4b
- Replies: 2
- Views: 325
Test #2 4b
Why wouldn't you put H2O(l) into the cell diagram the it is given on the cathode side?
- Tue Mar 12, 2019 9:25 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Formulas
- Replies: 6
- Views: 658
Re: Formulas
There are three equations that are given connecting Ecell, K and DeltaG if you're given one you can find the others.
- Tue Mar 12, 2019 9:11 pm
- Forum: General Rate Laws
- Topic: Equations
- Replies: 2
- Views: 341
Re: Equations
The reason why you haven't seen it on the constants and equations sheet is because we didn't need it for the two test or the midterm, but it will be on the final. The final constants and equations sheet should be on the Chem 14B website.
- Wed Mar 06, 2019 9:51 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3881492
Re: Post All Chemistry Jokes Here
What kind of fish is made out of 2 sodium atoms?
2Na
2Na
- Wed Mar 06, 2019 9:45 pm
- Forum: General Rate Laws
- Topic: Deriving Rate Laws
- Replies: 3
- Views: 426
Deriving Rate Laws
Will we have to be able to derive the rate laws for the final or just understand what is going on and how to use it?
- Wed Mar 06, 2019 9:41 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Instantaneous vs Average
- Replies: 11
- Views: 1067
Re: Instantaneous vs Average
average rate is when you take the change over time while instantaneous is usually when time is approaching zero and you take the derivative
- Wed Mar 06, 2019 9:39 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test #2
- Replies: 10
- Views: 1078
Re: Test #2
Tests are given back in your discussion section
- Wed Feb 27, 2019 7:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cell Diagram [ENDORSED]
- Replies: 3
- Views: 510
Galvanic Cell Diagram [ENDORSED]
In a galvanic cell diagram, I know we put a line between the solids and the aqueous solution and a comma between different aqueous molecules in the same beaker, but would we use a comma or a line to separate gas and aqueous in the same beaker?
- Sun Feb 24, 2019 3:23 pm
- Forum: Balancing Redox Reactions
- Topic: 6th edition 14.5a
- Replies: 1
- Views: 226
6th edition 14.5a
The problem asks you to balance the reaction using redox half rxns: O3 + Br- ----> O2 + BrO3-
For this problem O3 is oxidized = 0 to O2 which is -2, I thought O2 is suppose to equal 0 can anyone explain why and in what situations O2 would equal 0 or -2?
For this problem O3 is oxidized = 0 to O2 which is -2, I thought O2 is suppose to equal 0 can anyone explain why and in what situations O2 would equal 0 or -2?
- Sun Feb 24, 2019 1:05 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2
- Replies: 9
- Views: 1132
Test 2
What part of Gibbs Free Energy should we know for the second test?
- Thu Feb 14, 2019 11:59 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: 6th edition 9.11
- Replies: 1
- Views: 514
6th edition 9.11
Calculate the change in entropy when the pressure of 1.50 mol Ne(g) is decreased isothermally from 15.0 atm to 0.500 atm. Assume ideal behavior. I got the right answer for this problem using ΔS=nRln(P1/P2) = ΔS=(1mol)(8.314 J/k*mol)ln(15.0atm/0.500atm) = 42.2J/K but I'm confused how the units cancel...
- Sun Feb 10, 2019 2:20 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 8.73 Help (Bond Enthalpy)
- Replies: 2
- Views: 346
Re: 8.73 Help (Bond Enthalpy)
The solution only calculated the C-C bonds so there would be 3 mol of the CC triple bond broken and 6 mol of the C-C formed from the benzene ring.
- Sun Feb 10, 2019 2:16 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 3
- Views: 341
Re: Hess's Law
Usually the problem gives you values or tells you what method to use to solve for the enthalpy
- Mon Feb 04, 2019 2:35 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard formation deltaH
- Replies: 2
- Views: 338
Re: Standard formation deltaH
Standard Enthalpy of Formation (deltaH) is the most stable form of a molecule. You would use: ΔH(of formation) = Sum of ΔH(of formation of products) - ΔH(of formation of reactants). This is the 3rd method to find enthalpy changes from last weeks lecture.
- Sat Feb 02, 2019 1:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Week 5 Homework
- Replies: 4
- Views: 388
Week 5 Homework
What chapter is this week's homework suppose to be on? Do we continue with chapter 8?
- Sat Feb 02, 2019 1:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test Question
- Replies: 4
- Views: 484
Re: Test Question
Usually the problems specify whether to find the concentration or partial pressure, you can use Kc to also find the K of gases but I think they want us to use Kp for gases
- Sat Feb 02, 2019 1:35 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: U:Internal Energy
- Replies: 4
- Views: 452
Re: U:Internal Energy
They can both be used to find delta U depending on what's given in the problem. We also went over that when there is no volume change (in most of biology) then delta U = delta H.
- Wed Jan 30, 2019 9:29 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Homework #3
- Replies: 2
- Views: 323
Homework #3
Do we only do problems on thermochemistry chapter 8?
- Tue Jan 29, 2019 11:28 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Sig Figs with Enthalpy
- Replies: 4
- Views: 664
Re: Sig Figs with Enthalpy
Yes, use sig figs at the end when you add the enthalpies. I don't think they're that strict on it though.
- Thu Jan 24, 2019 11:31 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: converting between kp and kc
- Replies: 4
- Views: 468
Re: converting between kp and kc
There's also an equation that goes from Kc to Kp
Kp=Kc(RT)^delta(n) or Kp=(T/12.03)^delta(n)*Kc
Kp=Kc(RT)^delta(n) or Kp=(T/12.03)^delta(n)*Kc
- Thu Jan 24, 2019 10:42 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka and Kb values
- Replies: 1
- Views: 251
Ka and Kb values
I'm confused on how to select the correct Ka and Kb value from the table given in the textbook when they are not exactly what's in the problem. For example, in 12.71 to calculate the pH of 0.63M of NaCH3CO2(aq) would I just use the Ka value for acetic acid CH3COOH (1.8x10^-5)?
- Wed Jan 16, 2019 9:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE
- Replies: 5
- Views: 510
Re: ICE
X represents the change in concentration, it can either be positive or negative whether it is increasing or decreasing.
- Sun Jan 13, 2019 9:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibria Changes
- Replies: 3
- Views: 202
Re: Equilibria Changes
You would use the initial concentration mostly for the ICE table
- Sat Jan 12, 2019 1:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework 11.79 6th edition
- Replies: 2
- Views: 286
Homework 11.79 6th edition
What is the significance of using bar for units and what would be the easiest approach for problems like 11.79 6th edition? 11.79 A reactor for the production of ammonia by the Haber process is found to be at equilibrium with PN2 3.11 bar, PH2 1.64 bar, and PNH3 23.72 bar. If the partial press...