Molecular Definition and 583 Threads

Hello, This question is a theory question: I have calculated the moles of molecular iodine in a problem (I2) and the next question asks to calculate the moles of atomic iodine. Do I just multiply the number I have by two (as iodine is a diatomic molecule) or is it a "trick" question and the...

Alright, below are screen captures of some work that I'm tackling. They show my attempts and answers at the problems. I would like to know whether I'm correct or wrong and how to correct the mistakes. The one I need most help with is, the one where you're given density and asked to find...

MFA \hat{A}\hat{B}\approx \hat{A}\langle\hat{B}\rangle+\hat{B}\langle\hat{A}\rangle-\langle\hat{A}\rangle\langle\hat{B}\rangle What this mean physically? What we neglect here? If I calculate Neel temperature using this method T_N^{MFA} and using RPA method T_N^{RPA} is there some relation...

Hi I have read this and to put it mildly I am confused, so maybe someone can clear this up. The dew point is defined as the point/temperature at which the Partial Pressure of the water vapour within the air packet equals the Saturated Vapour Pressure. I understand that the dew point is a...

Homework Statement A student allowed a 0.500 gram sample of styrene to react with an excess of bromine.* An unknown product with a mass of 1.27 grams was obtained.**The student repeated the experiment several times and always obtained the same result.**What is the likely molecular formula of...

Hi, i am self studying quantum mechanics. I completed reading of "Quantum Physics_Eisberg, Resnick" and "Introduction to Quantum Mechanics - D. Griffiths". I want to study further on Atomic and Molecular quantum mechanics. Can anyone suggest me textbook on those topics? Thanks in advance.

complete combustion of 1.1g of a compound of C,H and O gives 2.2g of CO2 and 0.9g of H2O. The compound has a relative molar mass close to 130. Find the molecular formula and true molar mass? dont even no where to begin

Molecular "work" in an Adiabatic process ? I have studied Adiabatic cooling in connection with a rising parcel of air. I’m confused. I understand that temperature is a macroscopic principle (not a Microscopic); molecules do not have a temperature, only velocity and Kinetic energy. I have read...

I'm building a code for Molecular dynamics (in C). I'm employing Lennard Jones Potential, periodic border conditions and I integrate Newton's equations by making use of Verlet Integration. When I plot Time vs Energy graph, what I get isn't a constant! but when border condition are remove, then...

What technological challenges stand in the way of making molecular assemblers? I mean, what exactly would it entail to generate some sort of nanotechnology that could assemble, from scratch, a car or something? I've heard something about the "fat fingers" and "sticky fingers" problem and...

I would like to have a setup/software to geometrically simulate or represent the given molecule. For example I will input ; 2 hydrogen + 1 oxygen and it will output h2o and draw it's molecular shape. Also it would be much better if the software could give all the possible combinations of the...

If you increase mass with speed does the forces that hold molecules’ together increase in per portion ? If not do the molecules’ fall apart with speed ? If the forces increase in per portion Why does the energy released from the muluation of those forces decrease with speed.

Confusion with molecular geometry [carbon tetrachloride] I'm trying to understand the molecular geometry of four different compounds: CCl_{4} ,CHCl_{3} ,CH_{2}Cl_{2} ,CH_{3}Cl Please tell me whether my thinking is right or not[conceptually]. If it's wrong kindly correct me. for...

hi i am currently dealing with this problem here: i have some water and want to heat it up with microwaves. how do I determine the change in temperature of the water when i just know the characteristic features of the radiation? is there an equation for it? of course this process is not...

What would be a rough estimate of the computational complexity to simulate an embryo in a full-atom scale from the instant of conception to the death of the aging adult? Its a purely theoretical question and I know that its something like daydreaming for the current technology, but I would...

Iam really interested in molecular biology and microbial genetics, did masters in microbiology and want to get into doctoral program and do serious research in my interesting field. Is it not the good reason to get into phd.

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...

Can anybody tell me the significance of the band origin for a P(Q)R structure in the ultraviolet region of a molecules spectrum? In standard vibrational spectra, I understand that its roughly the harmonic frequency of the oscillator, and that the rotational constant can also be found from...

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...

Homework Statement http://s825.photobucket.com/albums/zz175/bobey/?action=view&current=bbb.jpg" The Attempt at a Solution my attempt to the question is as follow : W is the arrangement factor where N is the total number of states while n is the are the number of particles in energy state...

Hello PF, I've been given the daunting task of performing energy minimization calculations for my undergraduate research assignment. Is there someone with experience using TINKER? I wanted to use the dynamics.exe for calculations of a protein peptide sequence and it's asking me to enter a...

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)...

I want to simulate molecular diffusion in MATLAB. The idea is as follows: http://www.math.chalmers.se/Math/Grundutb/GU/MVG300/V11/Laborationer/anim1.jpg The picture represents a gas container and the red part is a barrier which the gas molecules cannot pass through except for the small...

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...

Im doing a study on a polyatomic molecule which is assigned by six quantum numbers, namely the three vibrational modes, and the Rotational quantum number J, and its projections on the A and C axes, (Ka and Kc): J, Ka, Kc, v1, v2, v3 Each combination of these numbers has an energy in...

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...

Hi, I have to calculate the Peclet number for a room. This room can be assumed to be at room temperature, and has a heat source within it which causes a temperature difference between the air near it, and the general room temperature. I have been unable to find an equation which will allow me...

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...