Molecules Definition and 543 Threads

So, I was playing around with this virtual lab online. I could add light gas or heavy gas to try to make the piston move. I got the same results using both gases..in other words, it took the same amount of light gas to move the piston as it did using heavy gas. Why is that? One would think it...

How many number of moles of molecules are there in 1 mol dm-3 of HCl? Is it correct to find it this way? Number of moles of HCl = 1 mol Number of moles of H2O = 1000/18 = 55.6 mol So, total number of moles = 55.6 + 1 = 56.6 molesIf i change the question of 3 mol dm-3 of HNO3, Then the total...

Homework Statement What is the total translational kinetic energy of the gas molecules of 0.450 mol of air at atmospheric pressure that occupies a volume of 5.00 L (0.00500 m3)? Homework Equations P=2/3(N/V)<Ktr> N= 0.450 mol V= 5.00L Want to find Ktr The Attempt at a Solution...

A hydrogen bond is the attractive force between one electronegative atom and a hydrogen covalently bonded to another electronegative atom. Doesn't this apply to hydrochloric acid?

Homework Statement For the following molecules, predict the order of their boiling points from highest to lowest. 1. CH_{3}F 2. C_{2}H_{6} 3. CH_{3}OH 4. C_{2}H_{4} The Attempt at a Solution I think the answer is 3 4 2 1. I put 3 first because it is an alcohol and has hydrogen...

Homework Statement A glass of water has a volume of 6.0 x 10*-4 cubic metres. How many moles of water molecules are there in the glass? Homework Equations The Attempt at a Solution I know it has something to do with Avogadro’s number but can’t figure out exactly what to do...

I've heard molecules are constantly moving or vibrating. What is the mechanism behind this? Where does the energy come from, and go? Is it always a function of temperature/pressure?

Homework Statement (a)What is the mean free path for oxygen molecules at 300K and atmospheric pressure (105 Pa) and the average frequency of collisions for a particular molecule? (The diameter of an oxygen molecule is 0.29 nm). (b)What is the mean free path of oxygen molecules at an...

I don't know how to distribute large amount of molecules(say a million) to many ro-vibrational states(say 100 states), according to the relative population of these states. As is very important when I want to simulate numerically the classical trajectory of these molecules in a spatially...

Homework Statement It is hard to imagine that there can be enough air between a book and a table so that there is a net upward (buoyant) force on the book despite the large downward force on the top of the book. About how many air molecules are there between a textbook and a table, if there is...

hello all how we can study the zeeman effect on molecule what is the bases to do it or it is the same for atoms.

Hello I was just revising for my Quantum Mechanics A exam and was considering the 1D double well model of an H2+ molecule. As I understand it Psi2 is non zero between the wells and therefore there is some negative charge present to which the H+ nuclei are attracted resulting in a covalent...

Consider a compressible fluid such as air. Assume we can neglect viscosity. We might describe such a fluid at some small region with a set of numbers. Three numbers would give the components of the velocity vector of the air at that small region and two more numbers would give the density and...

I've been doing some research on singlet-triplet molecular states, and one things I can't perfectly settle is a rigorous demonstration of why the triplet state is a higher energy than the singlet. One way I can qualitatively understand why the singlet state has lower energy is this: If the...

Does anyone know what the average distance between water molecules at rtp is, or how I could work this out? Thanks hgbreton

Homework Statement given that in a system, there are 5 % oxygen and 8 % nitrogen. it's also given the molecular mass of the two gasses. find the distance between molecules Homework Equations The Attempt at a Solution i don't know what the percentage is for. is it the percentage...

So far I've managed to draw a sort of diamond structure but i want to put spheres on some of the connecting vertices, put figuring out the angles and distances is quite tough, i was wondering whether there was any way of moving a sphere along a connecting vertex line directly. Any one any...

a) Show that the typical speed of air molecules in the room where you're sitting is about 500 m/s. b) Show that the typical speed is about 420 m/s at Mt. Everest. (Neglect the temperature difference between sea level and mountaintop, and assume that the air consists of only nitrogen...

Hi I'm currently studying cell biology, and I'm reading about the hydrophobic parts of the plasma membrane of the animal cell. But I'm wondering, what exactly makes a molecule hydrophilic or hydrophobic? What is the chemistry behind it, and how can I tell which molecules are which? I know that...

Homework Statement What volume of CH4 at 0°C and 1.00 atm contains the same number of molecules as 0.58 L of N2 measured at 35.0 °C and 1.50 atm? Homework Equations I think you just need to use Avogadro's Number and multiply by the molar mass? I guess my question is what equation would...

Homework Statement Think about forces between molecules, and explain why we might expect B(cm^3/mol) to be negative at low temperatures but positive at high temperatures. Homework Equations The Attempt at a Solution Well at low temperatures the motion of particles are not as...

Homework Statement 4.60×1023 nitrogen molecules collide with a 20.0cm^2 wall each second. Assume that the molecules all travel with a speed of 450m/s and strike the wall head on. What is the pressure on the wall in pascals (Pa)? Homework Equations p=(1/3)*(N/V)*(m*v_rms^2) where...

Hi, the question, I'm having problems with is this: A 1.0 mol sample of hydrogen gas has a temperature of 30 C. What is the total kinetic energy of all the gas molecules in the sample? How fast would a 75 kg person have to run to have the same kinetic energy? Relevant equations: K = (3/2)kT...

chemistry, how do i draw the lewis structures for these molecules? i have tried all sorts of ways but keep on geting stuck with atoms which i can't connect, don't have enough non paired valence electrons to join em all up H_{5}IO_{6} TeF_{6} IF_{7} SF_{4} BrCL_{3}

In high school I've been told that the molecules of gases have generally speed of severals kilometers per second. Hence why the wind is not always present, and why not that fast? (I guess it has to see with the huge number of particles... I never studied such a system in Physics yet, I...

Homework Statement In a period of 1 s, 5 x 10^23 nitrogen molecules strike a wall with an area of 8 cm^2. Assume the molecules move with a speed of 300 m/s and strike the wall head-on in elastic collisions. What is the pressure exerted on the wall? (The mass of one N2 molecule is 4.68 x...

Homework Statement I have a 3 compounds with the same formula: C6H12O2 I need to find the molecules by interpreting the H NMR spectroscopy http://aceorganic.pearsoncmg.com/epoch-plugin/tempfiles/1867_430.jpg http://aceorganic.pearsoncmg.com/epoch-plugin/tempfiles/1869_524.jpg...

Homework Statement What is the total number of atoms in the molecules? NH3 - 2.5 mole Homework Equations Would you multiply the number of atoms in NH3 by Avogadro constant to find the number of atoms? (4 atoms)(6.02*10^23) =answer Or would you multiply the number of moles by Avogadro...

If one considers an ideal gas, what does the mean time between collissions of the molecules depend upon? molecular size? number per unit volume? temperature of the gas? I'm thinking so far, it must def depend on number density. It would usually depend on molecular size (but I thought an ideal...

In a gas, do the molecular centers of gravity align significantly toward the dominant source of gravity? E. g., do atmospheric water vapor molecules tend to have their oxygen atoms facing Earth's center?

I am kind of confused by the conflict of the following two concepts. If I understood correctly, internal energy of a system is independent of the volume occupied by the gas molecules. This is because the gas molecules are assumed to be ideal and therefore have no intermolecular interactions...

Do the atoms in molecules separate quicker if they are moved more vigourously in their lifetime and therefoe cause death of the living organism they makes up sooner? For example: A giant tortoise is slower than a cheatah during its life and lives longer. A tree is slower than a tortoise and...

I have a question about something that has been bothering me for a while... In all of my chemistry classes, my professors have always told me that it is impossible to predict which way a chiral molecule will rotate plane-polarized light (i.e., you will see if a molecule is D or L, but, saying...

Hi, so glad to be here. This is my first posting. I'm just a 61 year-old dummy, so please help! If a rubber ball is dropped to a hard surface the impact will compress the rubber, storing some of the kinetic energy as potential elastic energy. The rebound will come from this stored potential...

Homework Statement a. On our planet, all air molecules are attracted by gravity. They should all gather closest to the Earth's surface. They don't. Why? b. Draw pictures of molecule distribution in a planet with very low gravity, and one with very high gravity. Homework Equations --...

How many molecules have a white blood cells and red blood cells? What are the chemical description and information about these above molecules?

CH3CH2CH2CH2OH A benzene ring with an OH group attached on the top and a NO2 group attached at the bottom. A benzene ring with an OH group attached on the top and a CH3 group attached at the bottom. A benzene ring with an OH group attached on the top And my question is, how...

[SOLVED] collisions of molecules.. Homework Statement a 10cm^3 box contains nitrogen at 20degreeC. What is the rate of collisions on one wal of he box. Homework Equations kb=1.38x10^-23 1u=1.661x10^-27 molecular mass of N2=28u avagadros number=6.02x10^23mol^-1 vrms=sqrt((3kbT/m))...

Do the molecules of a gas move randomly when they aren't colliding, or is it only when they have elastic collisions with other molecules? I know it's a retarded question, I don't know much about physics. Also, does the temperature of a body depend on the internal energy of it, or just kinetic...

I have thought of two possible explanations: a) Energy required to break H bonds = Energy released when H bonds form. There is a "constant" equilibrium in the system, meaning, some water molecules form H bonds, releasing energy to the environment which causes other water molecules to loose...

Homework Statement CHCl3 has M= 119 gmol^-1, density (rho) = 1.48 gcm^-3 Find the average separation between molecules in the liquid assuming a simple cubic packing Homework Equations The Attempt at a Solution I have found that there are 7.487x10^21 molecules cm^-3. Each...

Homework Statement At 100 Celcius the rms speed of nitrogen molecules is 576 m/s. Nitrogen at 100 Celcius and a pressure of 2.0 atm is held in a container with a 10cm x 10cm square wall. Homework Equations rate of collisions: N_coll/ \Deltat = (N*A*v_x)/(2V) (this is from my textbook) ideal...

I've been looking into LCD technology recently and have found a ton of sites that explain how twisted nematic crystals guide polarization of incident light and how LCDs work in general. But no one seems to explain which molecules are in fact twisted nematic crystals. can anyone tell me what...

Hey there guys i am new here and not sure if this is in the right section, well here goes. Just doing some revision and realized I must have been asleep for the Kinetic theory lessons, i have now grasped some of the basics, but have come to this question and not usre how to answer it...

Can anyone explain electromerism to me? If possible do mention some links. I've tried Googling it but I couldn't find much.

[SOLVED] reduced mass?! Hi there, I know the reduced mass is defining with the below formula: \frac{1}{\mu} = \frac{1}{m _{1}} + \frac{1}{m_{2}} + ... In Bohr's radius when i want to find the \mu i use the m1 = mass of electron m2 = mass of poroton but what if i need to find...

[SOLVED] average speed Problem: Calculate the average speed of a molecule that strikes a small surface. How does this compare with the average speed of all molecules? I started by using the root mean square speed as the average speed of some random molecule, for example hydrogen. So...

A diatomic molecule XY that contains a polar bond must be a polar molecule. A triatomic molecule XY2 that contains a polar bond does not necessarily form a polar molecule. I need some examples of real molecules to help me explain the difference. Thanks

How do you caclulate the average speed of a molecule? Is it the same as the volume? Thank you for your time.

I've lost track of this book. It must be 15 years old by now. But I really want to find it. Too bad I don't even remember what it's called - except that I'm sure it had the name molecules in it. This book was an intro to many of the common molecules we encounter in our lives. It started off...