Search found 21 matches

by Taylor Pio 3H
Wed Mar 09, 2016 11:11 pm
Forum: *Cycloalkenes
Topic: Winter 2012 Final 6A naming a cycloalkene
Replies: 1
Views: 333

Winter 2012 Final 6A naming a cycloalkene

For this question, there is a line structure of a cyclohexene. Between the first two carbons is a double bond. Attached to the second carbon (the end of the double bond) is a methyl group. The next carbon along the chain also has a methyl group, and the next carbon has two methyl groups. The solutio...
by Taylor Pio 3H
Wed Mar 09, 2016 10:49 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 2012 Final Q1B
Replies: 3
Views: 370

Re: 2012 Final Q1B

The q rxn found represents the DeltaH of that specific reaction. You divide by 4 because you must account for the fact that that q you just solved for represented the reaction of four moles of NO reacting. By dividing by 4 moles, you are left with units of kJ/mol, which are overarching and not speci...
by Taylor Pio 3H
Wed Mar 09, 2016 10:15 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Residual Entropy
Replies: 1
Views: 324

Re: Residual Entropy

Residual entropy is always taken at 0K. The equation to find this is S=kBlnW, W being the number of possible states it can take. While NO can take two possible states (NO and ON), BF3 can only take one (BF3), giving it a lower residual entropy. Hope this helps!
by Taylor Pio 3H
Tue Mar 01, 2016 9:18 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: determining molecularity 15.85 b
Replies: 2
Views: 353

determining molecularity 15.85 b

15.85 says that 2I-> I2 is termolecular. does this mean the molecularity is determined by the total reaction, and not the overall reaction?
by Taylor Pio 3H
Sun Feb 21, 2016 8:54 pm
Forum: General Rate Laws
Topic: Pseudo Rate Law
Replies: 2
Views: 1217

Re: Pseudo Rate Law

An important part of this law is the assumption that the other reactants are in large excess, and then you only measure the isolated, low-concentrate reactant.
by Taylor Pio 3H
Sun Feb 07, 2016 9:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Winter 2014 1C (Bond Enthalpies)
Replies: 2
Views: 373

Winter 2014 1C (Bond Enthalpies)

Why does the answer not take into account the energy to break the three C-H bonds in CH3OH?
by Taylor Pio 3H
Sun Feb 07, 2016 9:09 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 2011 midterm q4
Replies: 3
Views: 495

Re: 2011 midterm q4

I'm confused on why 2x is not the top. Wouldn't each reactant have a 1/2 in front of it? And then wouldn't you bring a 4 to the top instead of a two?
by Taylor Pio 3H
Mon Feb 01, 2016 7:05 pm
Forum: Balancing Redox Reactions
Topic: Ch. 14 #14.3a
Replies: 1
Views: 311

Re: Ch. 14 #14.3a

I believe that part of solving the problem involves you balancing the oxidation half-reaction, so the equation in its given state is not already equal on both sides. You must multiply by 4 in order to get an equal number of electrons on both sides of the equation. However, when I look at the solutio...
by Taylor Pio 3H
Fri Jan 22, 2016 7:09 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Calculating Reaction Enthalpy
Replies: 1
Views: 224

Calculating Reaction Enthalpy

For problems like 8.75 b, when looking at a molecule like CH3CHCH2 and CH3CH(OH)CH3, do I draw out the lewis structure to see which Carbons have double vs single bonds? Is this something I should intuitively know/is there a trick or select few I should know off of the top of my head without drawing ...
by Taylor Pio 3H
Sun Jan 17, 2016 8:07 am
Forum: Calculating Work of Expansion
Topic: Bond Formation Exothermic/Endothermic
Replies: 2
Views: 1014

Re: Bond Formation Exothermic/Endothermic

The formation of a bond takes energy that existed in two atoms and, because bonded atoms are more stable and have less energy, releases some of this energy to the outside environment. This would make the formation of a bond exothermic, as this energy is no longer contained and must go somewhere.
by Taylor Pio 3H
Tue Jan 12, 2016 9:55 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: When to use C=5/2R or C=3/2R
Replies: 7
Views: 1908

Re: When to use C=5/2R or C=3/2R

What does the R stand for in this equation?
by Taylor Pio 3H
Sun Jan 10, 2016 6:24 pm
Forum: Phase Changes & Related Calculations
Topic: Question 8.9
Replies: 3
Views: 1508

Re: Question 8.9

In 8.9, regarding the answer in the solutions, I follow that 1.48 L*atm comes from converting torr to atm and then multiplying by the change in volume. However, the solutions then suggest to convert to J using 8.314 J*K/mol over .08206 L*atm/K*mol. How do we know to use these? and how does the K can...
by Taylor Pio 3H
Sat Jan 09, 2016 11:33 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Which can be exchanged: matter or energy?
Replies: 4
Views: 688

Re: Which can be exchanged: matter or energy?

Matter in a closed system can not be exchanged with its surroundings, however the energy is still transferred between surroundings and system. Much like a saucepan with a lid on it on a stove, even though all the matter stays in the saucepan, it still is heated by its surroundings.
by Taylor Pio 3H
Fri Dec 04, 2015 9:15 pm
Forum: Photoelectric Effect
Topic: 2 on Fall 2008 Final
Replies: 1
Views: 380

2 on Fall 2008 Final

Q2A of theFall 2008 Final Exam asks: "In one photoelectric experiment the wavelength of an electron emitted from a metallic surface is 4.00 x 10^(-10) m. What is the velocity of the ejected electron in this experiment? The answer uses the equation v=h/m*lamba What is this and how is this equati...
by Taylor Pio 3H
Sun Nov 29, 2015 11:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: balanced reactions
Replies: 2
Views: 455

balanced reactions

Should we assume that questions and reactions given in questions are balanced? I ask because there was a question on quiz three (number 7 on my quiz) in which the given reaction was not balanced. My TA later explained to me that this was because an enzyme was left out of the given equation. Should w...
by Taylor Pio 3H
Sun Nov 15, 2015 8:49 pm
Forum: Bond Lengths & Energies
Topic: Stronger Ionic/Covalent Bonds
Replies: 3
Views: 973

Re: Stronger Ionic/Covalent Bonds

One way to determine which is stronger would be to calculate the dissociation energy, or how much energy it would take to break a bond. The greater this energy is, the stronger a bond is. Ionic bonds have a much higher dissociation energy than covalent bonds.
by Taylor Pio 3H
Sun Nov 08, 2015 11:26 pm
Forum: Bond Lengths & Energies
Topic: Bonding Orbitals versus Anti-Bonding Orbitals
Replies: 2
Views: 559

Bonding Orbitals versus Anti-Bonding Orbitals

Why is it that Anti-Bonding Orbitals are higher in energy than bonding orbitals?
by Taylor Pio 3H
Mon Nov 02, 2015 12:00 am
Forum: Photoelectric Effect
Topic: Wave-particle duality
Replies: 1
Views: 313

Re: Wave-particle duality

Emag radiation can be modeled as a wave in that it can be modeled with a variety of wavelengths and frequencies, and these models proved that light has properties of waves. however, in order to have a more thorough understanding of light, it is necessary to understand light as a particle, too. The d...
by Taylor Pio 3H
Sun Oct 25, 2015 10:49 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent Character
Replies: 2
Views: 439

Re: Ionic and Covalent Character

Even though all bonds between atoms have some covalent character (because the electron density is shared between the atoms), how ionic versus covalent a bond is gets determined by the difference in electronegativity between the atoms, not really by an atom's size. A larger difference points to a mor...
by Taylor Pio 3H
Sat Oct 10, 2015 12:07 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Removal
Replies: 1
Views: 345

Electron Removal

For Chapter 2, problem 47, part b, the question asks for the type of orbital from which an electron would be removed to form the +1 ion of Mn. I know that the Electron configuration is [Ar]3d5 4s2. Why does the solutions manual say the electron will come from 4s orbital, not 3d orbital?

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