All Questions
Tagged with degrees-of-freedom vibrations
17 questions
4
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590
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Why potential energy is not considered in the internal energy of diatomic molecules?
In thermodynamics, I am taught that there are 5 degrees of freedom in diatomic molecules since there are 3 for translational and 2 for rotational. I interpret degrees of freedom as "ways you can ...
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Why does $\rm{H_2 O}$ have 12 degrees of freedom?
I know there will be 3 translational D.O.F. and 3 rotational D.O.F., and it can have 4 vibrational D.O.F. (one potential and one kinetic) for each O-H Bond. But from where does 2 more D.O.F. come from?...
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How to know if the vibration system requires one degree of freedom or two? and how to pick the right coordinate to describe the movement?
I want to know a trick that helps me understand oscillatory systems and how to pick the correct general coordinates that describe the movement, I tried everything but I still can't get the solution ...
- 21
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Understanding vibrational mode of a molecule and its contribution to average energy
I'm facing difficulty understanding how vibrational energy modes contribute to a molecule's average energy (or heat capacity). What I know is : For a polyatomic non-linear molecule, there are $3N-6$ ...
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What are degrees of freedom in this context?
For translational motion,
$$H_\text{trans} = \frac{p_x^2}{2m} + \frac{p_y^2}{2m} + \frac{p_z^2}{2m}$$
For rotational motion,
$$H_\text{rot} = \frac{1}{2} \frac{L_x^2}{I_x} + \frac{1}{2} \frac{...
- 773
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2
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Degrees of freedom of gas molecules
What is the degrees of freedom of a three dimensional polyatomic molecule when only one vibrational mode is excited?
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2
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Degrees of freedom for diatomic molecules [duplicate]
I have a doubt in understanding about the degrees of freedom (dof) ......as I have learned dof is nothing but the necessary parameters to specify the location and configuration of a system.....if that'...
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1
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2 Extra Degree of Freedom in Linear Triatomic Molecules?
Ok, there is a bit problem in understanding Degree of Freedom of Linear Molecules specially of Triatomic Linear Molecules.
See, the DOF in general is given as $f=3N-k$.
Here,
N=Number of atoms in a ...
- 335
5
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2
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Actual Degree of Freedom of Diatomic Molecule
Ok, I have 2 very different values for degree of freedom(DOF) of diatomic molecules arising due to the difference in the vibrational DOF of the diatomic molecules.
According to this DOF wiki page:-
...
- 335
7
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1
answer
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Specific heat capacity vs KE gain of particles
To increase the temperature of 1kg of water by 1C you need 4200J of energy. However, the KE gain is only $\frac{3}{2} k_B \Delta T \cdot 6.02\cdot 10^{23} \cdot \frac{1000}{18} = 692.3$J. Where does ...
- 401
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Why does water have 9 degrees of freedom and that too all vibrational?
How does water has 9 degrees of freedom? If it can vibrate about all three atoms then why can't a diatomic molecule also have 2 instead of 1 possible vibrations?
I haven't studied quantum mechanics ...
- 644
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At what temperature does the vibrational degree of freedom becomes significant for an ideal diatomic molecule?
For ideal diatomic molecules such as $\text{H}_2$, $\text{N}_2$ and $\text{O}_2$, at what temperature does the vibrational degree of freedom significantly contributes to the calculations such as that ...
- 778
3
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1
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Degrees of freedom in a diatomic molecule [duplicate]
We know that a monatomic compound can only have 3 degrees of freedom as we can consider it to be a point mass. However now that we consider a diatomic molecule, there are 3 degrees of freedom in ...
- 427
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1
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The "potential energy" degree of freedom?
I'm reading Schroeder's "An Introduction to Thermal Physics" and he mentions the vibrational degrees of freedom of a diatomic molecule:
A diatomic molecule can also vibrate, as if the two atoms ...
- 181
8
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3
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6k
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Extra vibrational mode in linear molecule
When calculating the number of vibrational modes for a molecule, the formulas differ for linear $(n = 3N - 5)$ and non-linear $(n = 3N - 6)$ molecules, where $n$ is number of modes and $N$ is number ...
- 491
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In counting degrees of freedom of a linear molecule, why is rotation about the axis not counted?
I was reading about the equipartition theorem and I got the following quotations from my books:
A diatomic molecule like oxygen can rotate about two different axes. But rotation about the axis down ...
user36790
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What does degrees of freedom mean in the context of vibrations?
If you have an $N$ degrees of freedom system what does this mean?
What is the difference between a 1 and a 2 degrees of freedom system?
user43487