Molecular Definition and 545 Threads

Just curious why chemical physicists bother with localization procedures for molecules. Because atomic orbitals become de-localized when they form molecular bonds, but then it seems people wish to come up with procedures to re-localize. I've read quite a bit on how the de-localization...

Homework Statement 1)When 0.1mol of a hydride of nitrogen , Y, decomposes completely, it produces 0.3mol of gaseous elements. Y might be A)NH3 B)N2H4 C)N2H6 D)N3H6 2) Under the same conditions, 10cm3 of an oxide of nitrogen produces 10cm3 of nitrogen when reduced. The formula of the...

Is our current technology advanced enough to determine the exact opposite of a certain molecule or chemical? If we are not advanced enough, what would be required for this to be possible? Any thoughts on this please respond. I posted this in physics because there might be some advanced math...

I've been looking everywhere for information on the absorption spectra of molecular hydrogen. I need some pretty exact numbers. If anybody can point me in the right direction it would be greatly appreciated.

Hi, So I'm a phd student of physics, but my research overlaps a little with inorganic chemistry, specifically transition metal oxides and spectroscopies of them. I can glean some information MO diagrams and find them quite useful when writing about what I'm doing... however it's difficult to...

Molecular Cloud "Clumping" Question I have been told that mysterious 'density waves' hit molecular clouds and that these are what cause these large gas and dust fields to condense into stars and from there planets. What I don't understand is why don't we assume that the clouds own gravity...

Homework Statement What determines the order of the Molecular orbitals in heterodiatomics? The Attempt at a Solution In my book, I have NO with an order of 1s 2s 3s 1p 2p 4s Where s means sigma and p means pi. Also sometimes I see in the book the ordering being 1sigma...

I'm having a little trouble understanding the Sherwood number, (Sh, mass transfer Nusselt number), which gives the ratio of convective to diffusive mass transfer. My question is: given a system that has a molecular diffusion coefficient of D, the effective diffusion coefficient is measured to De...

I've always been curious about the following: What would happen to water on a molecular level if water were frozen but was unable to expand? Would it just not freeze? Or would the molecules lose their physical properties, particularly in relation to one another? And what would happen to...

All general chemistry textbooks have sections about molecular geometry, explaining that H2O is “bent”, NH3 is “trigonal pyramidal” and CH4 is “tetrahedral”, etc. But in a typical introductory textbook, it’s not easy to figure out how much is from experimental (observed) facts and how much is...

Homework Statement > 'from the form of the spherical harmonic function Y00=1/(sqrt(4pi)), what > can be said about the angular probability distribution of the ground state > of the hydrogen atom?' Homework Equations The Attempt at a Solution notes and textbook don't help its...

If I have a molecule of pb2SO4 for example, how would I draw that? What are the rules that tell me what attaches to what? When it's only 3 or 4 atoms, it's pretty easy to draw them, but when it's more than that, I have no clue what to do.

Homework Statement The molecular weight of a monoprotic acid HX was to be determined. A sample of 15.126 grams of HX was dissolved in distilled water and the volume were brought to exactly 250mL in a volumetric flask. Several 50mL portions of this solution were titrated against NaOH solution...

What is a wave function optimisation? What is a plane wave cut-off? Thanks

For classical molecular dynamics what does the classical bit refer to? What is non-classical molecular dynamics?

Homework Statement The hydrogen molecular ion , with one electron and two protons, is the simplest molecule. The equilibrium spacing between the protons is 0.11nm . Suppose the electron is at the midpoint between the protons and moving at 1.5 m/s perpendicular to a line between the protons...

I have some questions about molecular bonding. I understand that intramolecular bonds (forces holding a molecule together) are stronger than intermolecular bonds (forces between molecules). I also understand that the strength of intermolecular bonds determines whether something is gas (no bond)...

The study of viral particles has revealed significant information regarding protein folding. Many proteins hae been shown to often spontaneously fold into their functional structures and give an active viral particle. Yet some are incapable of proper folding on their own. It was shown in 1973...

Hello, I've been looking for a few rotational/vibrational diatomic molecular constants for N2 and O2. I've got a some good literature values for most constants I need involving the calculation in possible vibrational and rotational energy states. I'm looking for the centrifugal distortion...

[PLAIN]http://img560.imageshack.us/img560/6712/fizika5.jpg Homework Statement The electric energy is used to heat the liquid in the metalic bowl.. 1.Why is the liquid warmer at the top of the bowl than the bottom? 2. Why does the liquid's temperature raise faster if the metalic bowl has...

science book :) hi ,i am high school student it's my final year and i am interested in science . i am wondering about a book that i want to buy "cell and molecular biology by gerald karp" is it usefull for me .

I am a junior molecular biology major. I plan to go into graduate school and currently my #1 topic of interest is using solid state NMR to determine molecular structure. I am doing research on the unrelated topic of bacteriophage genomics but do not want to change labs because I am well...

Homework Statement A compound with a molecular weight of 110.1 g that contained only C, H, and O was analyzed by combustion. the combustion of a 5.19 g sample of the compound resulted in the formation of 12.4 g of carbon dioxide and 2.55 g of water. What is the molecular formulas of this...

Hello forum members, I got a nifty new multireference CI program at my hands and now I'm wondering what to do with it. The program is able to correlate general MCSCF wave functions, and as such basically any kind of molecular electronic structure imaginable; in particular also electronic...

Is their a method for predicting the molecular shape of molecules without drawing the Lewis structure? I am preparing for an ACS exam and would like to try to save some time on these problems. I think I could determine the steric number by counting the total electrons available, and...

Homework Statement I'm trying to figure out how to compute the average molecular weight of a gas mixture (nitrogen dioxide and dinitrogen tetroxide). I think I'm suppose to use this equation: M(mix)=X(NO2)M(NO2)+ X(N2O4)M(N2O4) , where I would just need to calculate the mole fractions and the...

These are practice problems (not hw) that I'm trying to work on, if anyone could help me out, thanks! I'm trying to find the net, ionic and molecular eq. 1)CaCO2+HCl=CaCl2+CO2(g)+H2O I just know that CO2 AND H2O doesn't break down because it's a gas and liquid. 2)NaHCO3+HBr=NaBr+CO2(g)+H2O

Few quick questions, too lazy to look up this info my self: 1. Whats the max molecular weight for a single polymer strand of styrne (i.e what's the max number of styrenes you can link up). 2. Anyone know about the industrial process to produce ABS? 3. What is a good solvent for Styrene...

I need to calculate the mean square speed of molecules in an ideal gas. Mean square speed is equal to 3RT/M, where M is the molecular weight. But what units do I use for the molecular weight if I use 0.08206 L.atm/(mol.K) as R? Thanks a lot.

DFT used electron density instead wavefunction, and in same time DFT use Schrodinger equation that use wavefunction. !?? so it still depend on wavefunction of Kohn-Sham and not depend on density only non interaction system wavefunction of still stand please I have many Paradox to...

Homework Statement 1.5000 g of diprotic weak acid H2A was dissolved in 100.00 mL volumetric flask. 25.00 mL aliqouts of this solution was titrated with a monoprotic strong base NaOH (0.08000 M). The titre volume of NaOH was 40.00 mL. Calculate the molecular weight of H2A. Homework...

Hi! I'm currently in 12th grade here in Hungary (= last year of high school), and have to decide which university I want to go to, and which course I want to take. I'm mainly interested in physics and a bit less in biology, programming and math. Don't get me wrong I like those as well, but...

NOT A HWK QUESTION! Molecular Theory PLEASE. Hi, Does anyone know the veracity of the quotation of experiments by Francis Bacon, in some books published around the turn of 20C., stating that he filled metal spheres with water and, upon applying sufficient pressure, saw water droplets on the...

Hi, Just wondering about the state of the literature regarding plane-wave molecular integrals. The coulomb potential seems to be causing problems for me. I assumed I would need to consider a general multipole expansion to integrate over a potential |r-r'|^-1 but I have had a look around and...

Homework Statement In his presentation of the de Broglie wavelength and the wave/particle duality, my quantum prof. has an exercise: "Find the de Broglie wavelength of a molecular vibration. Do quantum or classical laws apply?" Homework Equations wavelength = h/(momentum) ...

Homework Statement Greetings everyone I have been been asked to write a 10 page essay on Quantum Energy levels in atomic, molecular, nuclear and solid state physics. My problem is that this is such a huge topic and my knowledge of quantum energy levels and solid state physics is limited...

Now I'm undergrad student, majoring in Physics. But I think I prefer to be a physical chemist and want to be a university lecturer in department of chemistry. My research field is molecular biophysics and I need to have a basic knowledge of organic chemistry and biochemistry, but now I'm...

Is MO theory the most accurate model for atomic bonding we have so far? I've seen how it can be used to predict paramagnetism and diamagnetism but the idea of antibonding electrons and orbitals is seems fairly bizarre to me.

please tell me a quick for determination of empirical and molecular formula and also who invented it.

I don't know if this is a thermodynamics issue or a quantum mechanics one. It seems like there should be some relationship between the average heat and pressure of a system and the behavior of electrons orbiting nuclei. Does anyone know if there are any observations and experiments that have...

I know I know this isn't really related to molecular biology, but I figured since Biologists have a strong background in ecology in most cases, I'd be able to get more help here than the Earth forums (especially because biologists know a lot of chemistry). Basically I understand that CO2 keeps...

In my university (Catholic University of Leuven (Belgium) we have http://www.kuleuven.be/onderwijs/aanbod/opleidingen/E/SC_51017023.htm" with a few options: theoretical, nuclear, solid state, soft matter. I always wanted to do nuclear physics (and theoretical, but my math background isn't...

I have few questions regarding mercury vapor, except those related to health hazards. What is the mean molecular speed of mercury vapor at room temperature and speed of sound in a pure mercury vapor also at room temperature? Also, for the same density of air at seal level, can mercury...

Hello, I am interested in the electronic states of the N2 molecule. Now it is a homonuclear diatomic molecule and http://en.wikipedia.org/wiki/Molecular_term_symbol" ) but I do not understand what the Latin letters before the molecular term symbols mean. Here are some of the states X^{1}...

Could someone please help me get a very basic intuitive understanding of what rotational and vibrational quantum numbers mean? For simplicity, assume a diatomic molecule. For example, does a higher rotational quantum number mean that the molecule is rotating faster? Is the vibration number a...

From what I understand of nanotechnology, a lot of it is based around assembling individual molecules one by one to make superior materials such as graphene and nanotubes. If this is correct, will most materials be made out of carbon in the future (assuming that they are manufactured with...

Can someone explain to me, what are the factors/reasons that when certain atoms bond together, they form anti-Bonding or Bonding Molecular Orbitals? I am confused, and this is not in my syllabus(equivalent to Grade 12). P.S. It would be helpful if you included wavefunctions as well.

Homework Statement The relative motion of two atoms in a molecule can be described as the motion of a single body of mass m = 3 x 10-26 kg moving in one dimension, with a potential energy given by the equation U(r)=(A/(r^12))-(B/(r^12)) n this equation A = 10^10 J m^12 and B = 10^20 J m^6 are...

I understand half-lives, how various atoms decay through the various types of emissions (alpha, beta, gamma, etc). It's easy to do the math (or read the decay chain) for various things to see what the end-stable result if (eg U-238 and 235 decay to a thorium isotope, eventually to lead)...

what is the molecular formula of nitrite