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anony
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Homework Statement
Explain why molecules in water at room temperature behave like classical particles.
Homework Equations
[tex]E = \frac{3}{2}kT = \frac{p^{2}}{2m}[/tex]
[tex]p = \frac{h}{p}[/tex]
[tex]\lambda = \frac{h}{\sqrt{3mkT}}[/tex]
for room temp, T = 300K.
m is mass of water molecule
k is boltzmanns constant
The Attempt at a Solution
For classical behaviour the de broglie wavelength should be negligible in comparison to the interparticle spacing, [tex](\frac{V}{N})^{1/3}[/tex]. I remember this being told in the lectures.
I work out the mass m of a molecule by doing 18 x 10^-3 kg / avagadros number, and plug it into find the wavelength.
I work out the interparticle spacing by taking V = 1 litre = 10^-3 m^3, and N = 1 kg / mass of a molecule, and I find that the order of magnitude different is only a factor of 10. What have I done wrong?
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