Molecular Definition and 583 Threads

The ## {H_2^+}## molecule consists of two hydrogen nuclei and a single electron.What kind of molecular bond do you think holds this molecular together? Explain.

Trying to calculate the enthalpy of combustion for gasolines with different octane ratings, 95 and 91 gasoline in particular. The thing is, they are mixtures and not compounds. To calculate the enthalpy of combustion, I am trying to find the molecular formula for each of the gasolines, in order...

Summary: How do I draw the HOMO of HO-. The problem asks about the HOMO of HO- interacting in different ways with the LUMO of H-Cl. I cannot proceed with the question without figuring out how to draw the HOMO of HO-. I have attached pictures. Hello All, I have been struggling with this problem...

I am performing ab initio calculations on a heteronuclear diatomic compound using the MRCI method on the MOLPRO quantum chemistry package. I obtained the molecular states of the compound but I was wondering how to find the molecular orbital configuration of each electronic state in addition to...

We can calculate the average speed using this formula: uavg=root(8PV/ΠnM) I plugged in the following values: P= pi*10 atm (bar is approximately equal to atm) V=8lts n=2mol M=32*10^-3kg/mol But it is giving wrong answer. Can you tell me what went wrong?

Summary: Do solid particles rotate or transit or they just vibrate? Do solid particles move rotationaly and transitionally or all of these for liquid and gas?

Summary: How could we find the reduced mass for polyatomic molecule ? I have problem with reduced mass of poly atomic moleculs because for diatomic molecules you can easily find out the reduced mass by M¹M²/M¹+M²,but I don't think with this way we can find reduces mass for example for fe²o³?

Suppose you have a liquid with high potential energy at a height [H] in a first moment. In a second moment, the liquid loses its potential energy (that is converted into kinetic energy) and fall in a cylinder at height [h] .IF the liquid is incompressible what happens with the molecules in the...

Hello. I understand constructive/destructive interference for waves in general. But why do orbitals have phase? What is meant by phase for an orbital? What is the phase describing? Isn't the wave function describing where you are likely to locate the electron? Why is one positive and one...

So a photon is absorbed into and emitted from electrons, causing the electrons to jump energy levels around an atomic nucleus. And enough energy absorbed into the electron will cause the electron to break from the atom altogether. My question is, where does this energy that enters the...

During high vacuum pumping, one sucks viscous gas out of a chamber down to just above the molecular flow density where viscous flow becomes absent, and then may employ a different sort of pump to start pulling in the remaining molecules: Molecular flow. I have been wondering for a while if...

Apologies in advance if my understandings are simply incorrect. As I understand it, there is a limit to what can be known about both a particle's position and momentum, and in some interpretations this is because there is no position or momentum until measurement only a probability. What I am...

Found myself wondering about this recently, though I can't recall the context. When Mendeleev proposed the periodic table of elements, I believe that it was known that atomic weights of the known elements were multiples of hydrogen's atomic weight. Presumably also with substances like oxygen...

Good evening everyone. Can you tell me if it is possible to mathematically derive the Bernoulli principle from a microscopic analysis? In particular, in the hypothesis of an incompressible stationary flow, at a constant altitude, it states that: P + 0.5ρV^2 = cost Well, in textbooks this...

We are told that temperature measures the average kinetic energy of the molecules or atoms in a substance, but this cannot be true. If I take a jar of water and put the jar in my car and drive it aorund, it won't get hotter, though it's kinetic energy must surely be higher. Clearly, I've got...

Homework Statement I learned that Covalent Bonds form between different specific atoms ( with similar electro-negativity ) with electrons. However, I wondered what type of bond would form between the different atoms if they had no electrons? Also , if I have 2 atoms with similar...

im trying to jog my memory back 30years when I worked with vacuum tubes. I worked with manufacturing of image tubes. I remember the vacuum systems used vac-ion pumps to achieve -12 power torr. I alsoo remember first using a molecular seive for roughing,pumping to 10 microns. The seive was a...

Homework Statement In an organic compound "A" only C,H and O is present. 1.22g of A is completely burned and it gives 0.84g of CO2 and 0.54g of H2O. If the relative molecular mass of "A" is 123. Find the molecular formula of A. [/B] I have showed my attempt at solving this problem, but I think...

I'm not sure where this post belongs--here, or nuclear chemistry, quantum mechanics, NMR spectroscopy, etc. Moderator--please feel free to move it to a better location. I'm wondering if a container of liquid hydrogen subjected to a strong magnetic field would have both nuclei of each atom...

My chemistry teacher gave me this problem. I tried and tried, but I couldn't figure it out and the deadline is tomorrow. Please help me out here friends. 1. This is the problem : In a compound which is made of element Y, weight percentage of Y is 72% and N( Nitrogen) is 28%. Also, 3 Y atoms...

Diffusion of A through Non-diffusing B Dry air is required for burning of sulphur in a sulphuric acid plant. Moisture (A) diffuses through a film or layer of air (B), reaches the acid and gets absorbed in it. But air being virtually insoluble in sulphuric acid will not diffuse. So air is...

Homework Statement Freezing point depression question[/B] student determines molar mass of acetone using the method used in this experiment. She found that the eq temp of water and ice was 1 deg C. She then adds 11.1g of the sample to mixture and temp falls to -3 deg C. Mass of solution was...

Hi, currently I am a freshman who is majoring in Biosystems Engineering. I selected this major because I did a lot of research into biology undergrads and I didn't like what I saw. I got the notion that these majors did not emphasize the technical skills necessary to do well in a science...

I'm not a plant expert, but I can tell monocots from dicots. Apparently the monocot lineage was founded by aquatic plants (Science mag news story, original paper) and some obscure monocot leaf structure features can be explained by that aquatic origin. I'm actually kind of surprised...

The electrons in a molecule are said to be in a quantum superposition state in terms of their position/spin/momentum. But when you look at a molecule like water at a chemical level, it has a very specific shape corresponding to the P orbitals of the outer shell of the Oxygen atom. The two...

Homework Statement Menthol, the substance we can smell in mentholated cough drops, is composed of C, H, and O. A 0.1005-g sample of menthol is combusted, producing 0.2829 g of CO2 and 0.1159 g of H2O. What is the empirical formula for menthol? If menthol has a molar mass of 156 g/mol, what is...

Following Frekel-Smit book: https://www.amazon.it/dp/0122673514/ I am trying to write a program based on the algorithms 3,4,5 and 6 in the book. I use a cutted-shifted Lennard Jones potential, with cutoff radius at 2σ. #include <iostream> #include <cstdlib> #include <cmath> #include<fstream>...

Homework Statement [/B] A "molecular zipper" has two rows of molecules, and each row has a large number of monomers. A monomer from one row is weakly linked to a monomer in the other row. The zipper can unzip from one end by breaking the bond between pairs of monomers. A bond can be broken...

Who am I kidding? Of course it is. But, everywhere I look, the series of increasing levels of orbitals is till σ*2pz only That's all. So if I need to find bond order of , say, some molecule with greater number of e- like BF3 with 24 electrons, how do I proceed?

I’ve been reading up about Boltzmann transport equations, and the concept of molecular chaos has come up, in which one assumes the velocities of particles are assumed to be uncorrelated. I’m a bit confused about the concept though. In what sense do the velocities become correlated in the first...

Homework Statement Calculate the molecular weight of Al2(SO4)3.14.3H2O Homework EquationsThe Attempt at a Solution May i know how to do this ? Does it mean 14*3 = 42(H20) , where there re 84H , 42O atoms ?

Why is the enantiomer of a chiral molecule often considered to be a foreign, not-body-own pathogen? Peptidoglycan, which makes up a great part of the bacterial cell wall, contains several of these molecules, such as D-alanin, whereas humans use the L-form, or other components like L-glutamic...

Suppose I were to subject a polar molecule to a high-frequency electric field. The polar molecule responds to the high-frequency electric field and thus it has a time-varying electric dipole moment vector. If we treated this as a classical electric dipole, it would be expected to radiate some of...

Is there a word that describes physical bodies of molecules? By this, I mean any "body" that is composed of similar or different molecules, whether it is an ocean, a drop of water, a mountain, a glass cup, or a cloud, or even living bodies and their parts for that matter. This is in lines of...

My plan right now is to study a program called 'engineering physics with materials science' when I enter university in the fall. What I want to work with is molecular nanotechnology and programmable matter. I want to contribute to creating stuff like "computronium", utility fog, self-healing...

why are molecular vibrations never synchronized in a way that would make them macroscopically observable?

Hi all, I'm doing a bit of material science research at my university. I'm running molecular dynamics simulation programs like Lammps and Amber as part of it, and I'm pretty new to the whole thing (just like I'm pretty new to this forum). I'd like to ask, has anyone here used Amber to find their...

Homework Statement A beam of molecular oxygen containing 1010 molecules/cm3 and average speed of 500 m/s strikes (elastic collision) a plate at an angle of 30º with the normal direction. Calculate the exerted pressure on the plate. Homework Equations P = Impluse x Flux The Attempt at a...

I need good books on Molecular Orbital Theory. The book(s) should have the basics, and the level should not be less than graduation. I have Quantum mechanics books, but they don't throw any light on this. My course books are rubbish, only mentioning the name of the theory and some illogical...

This question is more about the maths than the physics. So I am reading the textbook by Bergersen and Plischke, and they get the following: $$m= \tanh [ \beta (qJm+h)]$$ where ##m## is the magnetization, ##q## is the number of nearest neighbours of site ##0##, ##J## and ##h##are the...

Hey all. I feel like I understand the topic mathematically, but I have little intuition behind this. I like to try to think about what is going on at the molecular level. I've recently learned that the basis of lift that I was taught in class is not simply a pressure difference on the top and...

Edit: thread moved from non HW forum. I'm trying to calculate the unit molecular weight of polystyrene. I'm given the structure, and I have to count all the elements in the structure. To calculate the weight, I keep counting 8C & 7H. The correct answer is 8C +8H. I'm having a hard time...

Homework Statement - How many grams of NaCl (molecular weight = 58 Da) would you have to dissolve in 50ml to make a 2M stock solution? The Attempt at a Solution I have thought about simply multiplying 58 by 0.1 = 5.8 g, but am not sure if this is correct. It's just the daltons that are...

Nucleus are entangled to electrons... Atoms are entangled to other atoms in molecules.. Are molecules at distance also entangled to one another? Is there a way to test if this is true? I want to know if our biochemistry is entangled to the biochemistry of other people.

Homework Statement A cylinder with a heavy ram/piston contains air at T = 300 K. Pi = 2.00 * 105 Pa, Vi = 0.350 m3, Mr = 28.9 g/mol & Cv = 5R/2 (a) What's the Molecular Specific Heat of an Ideal Gas, with a constant volume, computed at J/KgC ? (Cv) (b) What's the mass of the air inside the...

Has anyone owned the Scio pocket size molecular spectrometer that can make you identify substances? see https://www.consumerphysics.com/ how accurate is it? Is there a size limit for any spectrometer where accuracy could be affected? the Scio is an IR spectrometer.. is pocket size Raman...

I understand the fact that the detonator begins the reaction. The reaction happens many times release a ton of energy which causes the gases around it to rapidly expand and accelerate away (not the best summary). However, what causes the combustion which tends to happen as a consequence of the...

Homework Statement Suppose you were told you had a protein with molecular mass of 65,000 g/mol. Show how you would estimate the number of amino acids present in this protein. Keep in mind that you cannot calculate the exact number, the point of this is to approximate how many amino acids are...

Hi everybody, My post today is about Molecular Symmetry group (MS) for non-rigid molecules. I read from this excellent work (Longuet-Higgins), that MS is obtained by selecting only feasible operation from Complete Nuclear Permutation Inversion Group (CNPI). My question is, As I have a quite...

Hello everybody, I have read some very interesting book (Molecular symmetry and Spectroscopy - Bunker and Jensen) that talk about how to find the Molecular Symmetry group (MS) of a molecule by using the concept of "feasible" operation from the Complete Nuclear Permutation Inversion (CNPI)...