Search found 20 matches

by Allen Guo 4A
Sat Mar 12, 2016 10:28 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: New Newman Note
Replies: 1
Views: 289

New Newman Note

For a molecule like 2-chloro-propane, if you look down the C1-C2 bond, you can organize the the H, CL and CH3 around the C2 atom counterclockwise and clockwise differently, so do they have chemical differences, and if so is there a way to differentiate them?
by Allen Guo 4A
Sun Mar 06, 2016 10:28 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Torsional Strain
Replies: 2
Views: 296

Re: Torsional Strain

Torsional strain is the electron repulsion between two atoms when rotating around a bond. It is the reason why molecules prefer staggered formations over eclipsed ones.
by Allen Guo 4A
Sun Feb 28, 2016 9:31 pm
Forum: *Alkanes
Topic: Quiz 3 Preparation # 2
Replies: 3
Views: 326

Re: Quiz 3 Preparation # 2

Even though t comes before e in the alphabet, most prefixes are ignored in alphabetization, and ethyl comes before ethylpentane. If you compare 2 2 4 to 2 4 4, the first 2 is equal to the first 2 of the second scheme, but the first naming scheme's second digit, 2, is lower than the second digit of t...
by Allen Guo 4A
Sun Feb 21, 2016 9:01 pm
Forum: *Enzyme Kinetics
Topic: Two Paths
Replies: 5
Views: 761

Two Paths

Enzymes can lower the activation energy, but doesn't the reaction still occur without using the enzyme, meaning there are multiple paths?
by Allen Guo 4A
Sun Feb 14, 2016 11:06 pm
Forum: General Rate Laws
Topic: Changing Rate Orders
Replies: 1
Views: 239

Changing Rate Orders

Is it possible for reactions to change orders? For example, a zero order reaction could occur from a saturated catalyst, but after the reactant concentration has decreased enough, could it become a higher order reaction that is no longer solely dependent on the catalyst?
by Allen Guo 4A
Sun Feb 07, 2016 8:37 pm
Forum: Balancing Redox Reactions
Topic: Molecule being both reduce and oxidized
Replies: 1
Views: 202

Re: Molecule being both reduce and oxidized

This would be an example of a disproportionation reaction. You might want to show one Cl atom becoming Cl- in a reduction and a Cl atom becoming HClO being oxidized.
by Allen Guo 4A
Sun Jan 31, 2016 9:00 pm
Forum: Balancing Redox Reactions
Topic: Dissolving Gold
Replies: 1
Views: 314

Dissolving Gold

During the lecture, Dr. Lavelle discussed how the nitric acid would not dissolve the gold ring to a 1 M solution, but would some gold still be dissolved, just not to 1 M concentration?
by Allen Guo 4A
Sun Jan 24, 2016 10:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reversible vs Irreversible Process
Replies: 2
Views: 427

Re: Reversible vs Irreversible Process

In the reversible process, the volume slowly changes because pressure/weight on the other side of the piston is decreased infinitely slowly. The surroundings act as a heat sink keeping the system at a constant temperature, so reversible processes are the ones with unchanging temperature. Additionall...
by Allen Guo 4A
Sun Jan 17, 2016 8:11 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat of Combustion
Replies: 1
Views: 286

Heat of Combustion

For a problem like 8.57, where it gives you the heat of combustion, could you treat the heat of combustion as the negative enthalpy of formation for the problem? Even though combustion ends up with CO2 and H2O, it is similar to the standard states since all the reactants and products of the original...
by Allen Guo 4A
Sat Jan 09, 2016 5:18 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard States
Replies: 1
Views: 241

Standard States

Is the standard state for an element the form with the lowest energy at STP, and if so, would the enthalpy of formation for a substance from elements not in their standard states always be lower or higher than the standard enthalpy of formation?
by Allen Guo 4A
Tue Dec 01, 2015 10:22 pm
Forum: *Titrations & Titration Calculations
Topic: Stoichimetric Point
Replies: 2
Views: 325

Re: Stoichimetric Point

pH is -log[H+], meaning the concentration must change by tenfold for pH to change by one. The stoichiometric point is where there is a small amount of acid/base affecting the pH, so an increase in ten of the H+ concentration isn't hard to achieve. When there is already a lot of acid or base (when it...
by Allen Guo 4A
Sun Nov 29, 2015 12:27 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH of a very weak acid
Replies: 1
Views: 324

Calculating pH of a very weak acid

If I find the concentration of H3O+ to be around 10^-7, would I need to recalculate the concentration by setting the initial concentration of hydronium ions to 10^-7? If a very small amount of H3O+ was produced, like 10^-10, the pH would still be close to 7, but what is the cut-off?
by Allen Guo 4A
Fri Nov 20, 2015 7:30 pm
Forum: Polyprotic Acids & Bases
Topic: Water
Replies: 1
Views: 418

Water

If water molecules can rip protons from each other to form OH(-) and H3O(+), is it possible (even if it is very unlikely) for H3O(+) to gain another proton to form H4O(+2), or for OH(-) to become O(-2). In water, do H3O(+) ions ever give a proton to a H2O molecule, or is the proton stuck to it until...
by Allen Guo 4A
Sun Nov 15, 2015 11:43 am
Forum: Naming
Topic: Bromo Vs. Bromido
Replies: 1
Views: 694

Re: Bromo Vs. Bromido

On the course reader, page 105, Bromo is the old name, and what "We use," and Bromido is under the "New IUPAC Name Convention." However, it says you can use either one, so it shouldn't really matter.
by Allen Guo 4A
Sun Nov 08, 2015 2:45 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals and Octets
Replies: 1
Views: 255

Transition Metals and Octets

Atoms generally want to form an octet to become stable, so why do transition metals usually get six coordinate covalent bonds, and would the transition metals have to hybridize d-orbitals for the bonding?
by Allen Guo 4A
Sat Oct 31, 2015 8:52 pm
Forum: Bond Lengths & Energies
Topic: Exciting Bonding
Replies: 1
Views: 307

Exciting Bonding

Is it possible for excited electrons to participate in bonding, and if so, what changes would occur?
by Allen Guo 4A
Wed Oct 21, 2015 11:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar Angles
Replies: 4
Views: 1177

Re: Square Planar Angles

In a square planar, the lone pairs are on opposite sides of the central atom, keeping the four bonding electron pairs on one plane. The bonding pairs experience equal repulsion from both lone pairs, so 4 bonds split on a 2-D plane is 90 degrees of separation between each bonding pair. However, what ...
by Allen Guo 4A
Fri Oct 16, 2015 4:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Structure and Resonance
Replies: 1
Views: 274

Re: Molecular Structure and Resonance

Resonance occurs when there are multiple stable forms for a molecule when the atoms are in the same orientation, but the electrons are not, so the shape should be the same, and the actual structure is a blend of the different electron positions.
by Allen Guo 4A
Fri Oct 09, 2015 4:42 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Removing Electrons
Replies: 1
Views: 278

Removing Electrons

When an electron is removed from an atom, like Titanium, it was explained that it is removed from the 4s orbital because they are on the outside. However, why don't the 3d electrons fill in the 4s spot since when filling the orbitals, 4s comes before 3d and being in 4s should be stabler than in 3d.
by Allen Guo 4A
Sun Oct 04, 2015 5:34 pm
Forum: DeBroglie Equation
Topic: De Broglie Question
Replies: 1
Views: 414

De Broglie Question

It was mentioned that wave-like properties are only noticed for objects with small mass and high velocity, but wouldn't raising the velocity in "wavelength = h/(m*v)" make wavelength smaller while lowering mass makes wavelength larger?

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