Search found 28 matches

by Michael Le 2D
Sat Mar 12, 2016 8:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Final 2014 question 3A pikachu
Replies: 2
Views: 475

Re: Final 2014 question 3A pikachu

There's also a reduction reaction that utilizes the NO3 ion and that has an E of .96V. Why isn't this used?
by Michael Le 2D
Fri Mar 11, 2016 9:59 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Residual Entropy of NO compared to BF3
Replies: 3
Views: 810

Re: Residual Entropy of NO compared to BF3

What's the difference between NO and ON?
by Michael Le 2D
Sun Feb 28, 2016 2:30 pm
Forum: *Electrophiles
Topic: NO2+ as an electrophile
Replies: 1
Views: 1777

NO2+ as an electrophile

Upon drawing NO2+ or in the book +NO2 all of the elements have a complete octet. Why is it then an electrophile?
by Michael Le 2D
Wed Feb 24, 2016 5:21 pm
Forum: *Cycloalkenes
Topic: Benzene
Replies: 2
Views: 480

Benzene

Benzene has a ring structure and multiple double bonds. Why isn't it called uh... 1,3,5 cyclohexatriene? I'm not sure if that's correct but at least why isn't there a cyclo - ?
by Michael Le 2D
Wed Feb 24, 2016 5:06 pm
Forum: *Electrophilic Addition
Topic: Electrophile
Replies: 2
Views: 329

Re: Electrophile

A good way to remember this is that phile means 'loving' ... therefore electrophile -> electron loving (which eventually you can deduce is because they are electron deficient). This will allow you to remember that they are partial positive, attracted by electrons, etc.
by Michael Le 2D
Wed Feb 24, 2016 4:58 pm
Forum: *Electrophiles
Topic: Transition States
Replies: 2
Views: 418

Re: Transition States

Additionally, the delta G is actually the difference between TS2 and the intermediate NOT the reactant. This is important!
by Michael Le 2D
Fri Feb 19, 2016 5:38 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Intermediates vs. Transition States
Replies: 3
Views: 3400

Re: Intermediates vs. Transition States

Per my understanding, intermediates are a sort of middle ground between reactants and products. A reactant becomes an intermediate and then this intermediate becomes a product. Transition states are HOW these these species are transforming. Transition states involve bonds IN THE PROCESS of breaking/...
by Michael Le 2D
Thu Feb 11, 2016 3:05 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Potential Increase/Decrease
Replies: 2
Views: 387

Re: Cell Potential Increase/Decrease

Cell potential increases and decreases are dictated by the parameters in the Nernst equation (mols of electron, temperature, concentration of ions in cell).
by Michael Le 2D
Thu Feb 11, 2016 3:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Effects of Adding Reactants and Products
Replies: 1
Views: 326

Re: Effects of Adding Reactants and Products

Just think of it in terms of Le Chatelier's Principle. Removing a product will force the reaction to the right and encourage this forward reaction (which encourages electron production) thereby increasing E over E (naut or E standard). The same goes for removing a reactant or adding some product.
by Michael Le 2D
Thu Feb 04, 2016 3:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Reduction Potential Calculations
Replies: 1
Views: 266

Re: Standard Reduction Potential Calculations

Yes! You need to multiple the standard potential given by -1. Although if you multiply the entire reaction with some stoichiometric scalar (say you need 2 mols of Cu+ instead of just 1), the standard potential remains the same. This is because standard reduction potential gives the voltage differenc...
by Michael Le 2D
Wed Jan 27, 2016 9:55 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: problem 8.67 b
Replies: 1
Views: 300

Re: problem 8.67 b

Hello! It is given in the problem as the enthalpy of sublimation.
by Michael Le 2D
Thu Jan 21, 2016 3:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Picking up the final
Replies: 1
Views: 628

Picking up the final

I don't have my course reader any longer; where is the office where we can pick up our fall quarter finals and when is the office open?
by Michael Le 2D
Sun Jan 17, 2016 10:28 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Help Breaking Down 8.25
Replies: 1
Views: 248

Re: Help Breaking Down 8.25

Additionally, the solution manual notes that q cal = C*deltaT... a positive value for q despite the temperature rising 7.32 degrees celsius. Does that mean the heat came from the calorimeter into the water?
by Michael Le 2D
Thu Jan 14, 2016 12:01 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 1
Views: 365

Re: Bond Enthalpies

I was under the impression that we broke all the bonds that weren't repeated (this becomes apparent when one counts the bonds from reactants and products and see say, two X-Y bonds). If one broke all the bonds and included all of the bond formations these values would inherently cancel anyhow. I'm n...
by Michael Le 2D
Wed Jan 06, 2016 3:40 pm
Forum: Phase Changes & Related Calculations
Topic: Steam v Water
Replies: 4
Views: 726

Re: Steam v Water

https://scienceisntscary.files.wordpress.com/2013/05/heating-curve.png This is the explanation in a graphical sense. If we visualize just the boiling water (the leftmost point on the red colored line), we see that the heat added which is the heat that transfers into the skin when the skin comes in ...
by Michael Le 2D
Wed Dec 02, 2015 7:43 pm
Forum: *Titrations & Titration Calculations
Topic: Titration curve question
Replies: 2
Views: 595

Re: Titration curve question

I believe this point is also called the halfway point.
by Michael Le 2D
Wed Dec 02, 2015 7:41 pm
Forum: *Titrations & Titration Calculations
Topic: What are the different names for stoichiometric point?
Replies: 1
Views: 421

Re: What are the different names for stoichiometric point?

Stoichiometric and equivalence points are synonymous. I believe the halfway point refers to weak/strong titrations and the actual point occurs when pH=pkA/pkB. I believe it is halfway to the stoichiometric point.
by Michael Le 2D
Mon Nov 30, 2015 2:49 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Buffers
Replies: 2
Views: 504

Re: Buffers

I believe strong acids and bases are poor buffers because their respective conjugate bases/acids are extremely weak. In order to be an effective buffer, both the acid and its conjugate base have to be relatively weak. Check this picture out for a graphical representation: http://forums.studentdoctor...
by Michael Le 2D
Sat Nov 14, 2015 7:07 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: EDTA binding sites
Replies: 1
Views: 1043

EDTA binding sites

http://www.chemgapedia.de/vsengine/media/width/247/height/178/vsc/de/ch/16/biochem/grafik/edta.svg.jpg Looking at the 4 oxygens with a - and the two nitrogens with one lone pair makes EDTA have six lone pair binding sites. Why are we not taking into account the oxygens that are double bonded, don't...
by Michael Le 2D
Sat Nov 14, 2015 6:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to determine monodentate or bidentate?
Replies: 3
Views: 3857

Re: How to determine monodentate or bidentate?

In this case Dr. Lavelle, why is it that CO3 (2-) can be bidentate. Considering that H2O has angles of 109.5 between the lone pairs and can only form 1 binding site how come the 120 degrees (> than 109.5) in CO3 (2-) can form two binding sites despite being wider than water?
by Michael Le 2D
Sat Nov 14, 2015 6:47 pm
Forum: Naming
Topic: Bisoxalato vs. Dioxalato
Replies: 1
Views: 1099

Bisoxalato vs. Dioxalato

For ligands such as ethylene DI amine(en) or ethylene DI amine TETRA acetato (EDTA), I understand that we have to use bis, tris, tetrakis when referring to multiple of these ligands. For oxalato in question 17.31D, oxalato is referred to as bisoxalato. Why not dioxalato for this ligand considering t...
by Michael Le 2D
Fri Nov 13, 2015 8:32 am
Forum: Sigma & Pi Bonds
Topic: Identifying the composition of bonds/hybridizations notation
Replies: 2
Views: 572

Re: Identifying the composition of bonds/hybridizations nota

Given a lewis structure we'll know the number of sigma/pi bonds just given the number of single/double/triple bonds. Sigma for all single bonds and pi bonds for anything above so (doubles are 1 sig 1 pi, triples are 1 sig 2 pi). As for that hybridization notation we'll have to figure out which orbit...
by Michael Le 2D
Sat Oct 31, 2015 10:55 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonding Molecular Orbital Energies
Replies: 1
Views: 220

Bonding Molecular Orbital Energies

Why is it that sigma bonds are lower energy than pi bonds but in atoms with z>8, their anti bonding counterparts are higher nrg than the pi bonds. What exactly is an anti bonding orbital? We can see the sigma and pi bonds in a molecules 3D bond representation but can we see the anti bonding orbitals?
by Michael Le 2D
Fri Oct 30, 2015 1:46 am
Forum: Dipole Moments
Topic: Dipole moments with vectors
Replies: 1
Views: 408

Dipole moments with vectors

The debye was introduced in the course reader; for molecules such as CCl3F, how do we know if the dipole is towards the Cls or towards the F. We know that the F-C difference is greatest and its individual dipole will be the strongest but if we add the dipole moments as vectors with units debye, are ...
by Michael Le 2D
Sun Oct 18, 2015 10:29 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarisability
Replies: 1
Views: 326

Polarisability

Assuming different elemental sizes, why is it that the cation charge (+2 or +3 etc.) is such a big determinant of an element's polarizing power. For example, I understand that Be2+ is much smaller than Sr2+ but the high powered nucleus of Strontium isn't enough to overcome the electron repulsions an...
by Michael Le 2D
Sat Oct 10, 2015 1:19 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Penetration
Replies: 2
Views: 522

Penetration

The book in chapter 2.5 describes inner-shell electrons as having a "penetrating effect." This is also seen in question #2.37 which states that electrons in an s-orbital are more effective than those in other orbitals at shielding from the nuclear charger because an electron in an s-orbita...
by Michael Le 2D
Wed Oct 07, 2015 5:44 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Experiment
Replies: 1
Views: 255

Heisenberg Indeterminacy Experiment

In the experiment that led to Heisenberg's Indeterminacy equation, a major point was that the distance that the electron traveled could not be calculated with certainty because we weren't sure how much it had been deflected off of its path. Hypothetically speaking, if we were to set up a pair of sen...
by Michael Le 2D
Thu Oct 01, 2015 12:07 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: How many photos of infrared radiation?
Replies: 1
Views: 335

How many photos of infrared radiation?

In 1.0 s, a 60 W bulb emits 11 J of energy in the form of infrared radiation (heat) of wavelength 1850 nm. What is the energy per photon of light emitted? How many photons of infrared radiation does the lamp generate in 1.0 s? So I understand how to do the first part of the problem but I'm not reall...

Go to advanced search