Search found 25 matches
- Tue Mar 14, 2017 10:49 pm
- Forum: Balancing Redox Reactions
- Topic: Winter 2016 Midterm, Question 6
- Replies: 2
- Views: 665
Re: Winter 2016 Midterm, Question 6
Thank you!
- Tue Mar 14, 2017 8:53 pm
- Forum: Balancing Redox Reactions
- Topic: Winter 2016 Midterm, Question 6
- Replies: 2
- Views: 665
Winter 2016 Midterm, Question 6
For this problem we have to write and the balance reduction and oxidation half reactions in part a & b for H + (aq)+Cr 2 O 7 2- (aq)+C 2 H 5 OH(aq)-->Cr 3+ +C 2 H 4 )(aq)+H 2 O(l) In part A, there is 2 electrons in the oxidation half reaction. Why is it 2 electrons instead of 1 if C goes from 2-...
- Tue Mar 07, 2017 8:13 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Transition State and Psuedo-Equilibrium Rate Constant
- Replies: 1
- Views: 505
Transition State and Psuedo-Equilibrium Rate Constant
I'm a bit confused about pages 85 and 86 in the course reader. On page 85, how can we tell that step 1 has a higher energy barrier? On page 86, what exactly is the psuedo-equilibrium constant and when/how is it used?
- Thu Mar 02, 2017 5:46 pm
- Forum: *Electrophiles
- Topic: Neither electrophile nor nucleophile
- Replies: 2
- Views: 5377
Neither electrophile nor nucleophile
What is an example of something that is neither an electrophile nor a nucleophile? Does such exist?
- Mon Feb 20, 2017 10:12 pm
- Forum: General Rate Laws
- Topic: Rates
- Replies: 1
- Views: 559
Rates
What is the difference between average rate and instantaneous rate?
- Sun Feb 12, 2017 1:04 am
- Forum: Balancing Redox Reactions
- Topic: Midterm 2013, Q7
- Replies: 5
- Views: 1009
Re: Midterm 2013, Q7
Anyone here know if we will need to balance out the hydrogen and oxygen the half reactions for the midterm?
- Thu Feb 09, 2017 3:42 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: equations
- Replies: 1
- Views: 508
equations
There are various ways to calculate the work of an isobaric reaction such as w=-P(deltaV), w=-nR(deltaT), and w=-(deltan)RT. This also goes for calculating change in entropy, enthalpy, and heat. I am aware that some equations are listed but not all of them are. Will we be given the different equatio...
- Wed Feb 01, 2017 11:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 1 Preparation Answers
- Replies: 130
- Views: 25692
Re: Quiz 1 Preparation Answers
#8 on Quiz 1 Preparation says, "For reaction: 2C+2H2=C2H4, DeltaH= +52.3 kJ/mol and DeltaS= -53.07 J/K*mol at 298 K. At what temperature will this reaction be spontaneous?" Initially, I thought the formula needed to solve for the temperature was DeltaG= DeltaH - T*DeltaS but then I saw th...
- Wed Feb 01, 2017 5:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 1 Preparation Answers
- Replies: 130
- Views: 25692
Re: Quiz 1 Preparation Answers
For #11, do the units not have to cancel out?
- Wed Jan 25, 2017 11:08 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Integral
- Replies: 1
- Views: 507
Integral
When taking the negative integral from the initial volume to the final volume, why is PEX the integrand instead of PINT? found on page 22 of the course reader
- Thu Jan 19, 2017 8:18 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Chapter 8, Problem 61
- Replies: 5
- Views: 1503
Re: Chapter 8, Problem 61
How do you know when you have to reverse the equation?
- Thu Jan 19, 2017 7:57 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Chapter 8, Problem 61
- Replies: 5
- Views: 1503
Chapter 8, Problem 61
Calculate the reaction enthalpy for the synthesis of hydrogen bromide gas, H 2 (g)+Br 2 (l) -> 2HBr. The problem gives you 3 equations and their enthalpies but how do you use the three equations to obtain the reaction enthalpy for H 2 (g)+Br 2 (l) -> 2HBr. I tried to combine the equations like I did...
- Sun Jan 15, 2017 5:12 pm
- Forum: Phase Changes & Related Calculations
- Topic: CLOSED vs ISOLATED
- Replies: 3
- Views: 814
CLOSED vs ISOLATED
What is the difference between the two? How does the energy exchange with the surroundings?
- Wed Nov 30, 2016 2:06 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Hydronium and Hydroxide
- Replies: 2
- Views: 695
Hydronium and Hydroxide
Why do we use H2O and H3O+ when writing out equations?
- Wed Nov 23, 2016 1:47 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE TABLE
- Replies: 1
- Views: 552
ICE TABLE
Can someone please explain how to use the ice table and how to find the change in molar concentration (-x, x, 2x, etc...)?
Thank you!
Thank you!
- Tue Nov 15, 2016 4:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: #4 in Quiz Prep 3 2015 [ENDORSED]
- Replies: 1
- Views: 586
#4 in Quiz Prep 3 2015 [ENDORSED]
For [Fe(Cl)4(en)]2- I got a coordination number of 5 because of the 4 Chlorine and the one ethelynediammine but the answer is 6. Am I supposed to count en as 2 bonds?
- Tue Nov 08, 2016 10:36 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Cholorophyll Example in Course Reader
- Replies: 1
- Views: 437
Cholorophyll Example in Course Reader
How is the MO Theory applied in the chlorophyll example on page 112 of the course reader?
- Fri Nov 04, 2016 11:29 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3635822
Re: Post All Chemistry Jokes Here
Anyone know any jokes about sodium?
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Na
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Na
- Mon Oct 24, 2016 12:13 pm
- Forum: Trends in The Periodic Table
- Topic: CH 2, #61 [ENDORSED]
- Replies: 2
- Views: 669
CH 2, #61 [ENDORSED]
Which member of each pair has the smaller first ionization energy:
a) Ca or Mg; b) Mg or Na; c) Al or Na
How do you determine which is smaller? Should you refer to the periodic table? Also, does the "first ionization energy" just imply Ca+ and Mg+ or is it something different?
Thank you!
a) Ca or Mg; b) Mg or Na; c) Al or Na
How do you determine which is smaller? Should you refer to the periodic table? Also, does the "first ionization energy" just imply Ca+ and Mg+ or is it something different?
Thank you!
- Tue Oct 18, 2016 9:35 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Aufbau's Principle [ENDORSED]
- Replies: 3
- Views: 836
Re: Aufbau's Principle [ENDORSED]
Is this always the case or does it depend on the atom?
- Mon Oct 17, 2016 3:51 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Aufbau's Principle [ENDORSED]
- Replies: 3
- Views: 836
Aufbau's Principle [ENDORSED]
I'm not sure if someone already asked this but I'm still a bit confused. According to Aufbau's Principle 4s comes before 3d, but in the course reader for Scandium, 3d goes before 4s. Is Scandium an exception?
- Fri Oct 14, 2016 10:36 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3635822
Re: Post All Chemistry Jokes Here
What do you get when you cut an avocado into 6.0x10^23 pieces?
Guacamole!
Guacamole!
- Wed Oct 05, 2016 3:47 pm
- Forum: *Shrodinger Equation
- Topic: psi
- Replies: 1
- Views: 668
psi
Is psi basically equal to the amplitude? And how can you find an electron with psi^2?
- Wed Sep 28, 2016 4:39 pm
- Forum: General Science Questions
- Topic: Memorizing Constants
- Replies: 2
- Views: 836
Memorizing Constants
Are we expected to have constants like Avagadro's Number and Planck's constant memorized or will they always be given?
- Mon Sep 26, 2016 7:49 pm
- Forum: Significant Figures
- Topic: Easy Way to Calculate Sigfigs
- Replies: 6
- Views: 1554
Re: Easy Way to Calculate Sigfigs
So in other words,"trailing zeroes" are counted as significant figures if a decimal in present? Or am I interpreting that video wrong...?