Question

What is the average kinetic energy of 1 mole of a gas at 125 Kelvin? (R = 8.314 J/K-mol)
A. 1.04 x 10^3 J

B. 3.12 x 10^3 J

C. 1.56 x 10^3 J

D. 1.77 x 10^3 J

Answer 1

do you know equation for average kinetic energy

Answer 2

From kinetic theory,
\[E_K=\frac{1}{2}m<c^2>=\frac{3}{2}k_BT\]
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We can say that
\[E_K=\frac{3}{2}k_BT\]
\(k_B=Boltzmann~Constant=1.38 \times 10^{-23}m^2kgs^{-2}K^{-1}\)
Substitute in
\[E_K=\frac{3}{2}(1.38 \times 10^{-23})(125)=?\]
Multiply that by avogadro number \(N_A\) gives average kinetic energy

Answer 3

@chmvijay do you have a different approach? I can't think of one relating R

Answer 4

ur right i is 3KT/2

Answer 5

yeah but the problem is the question includes (R = 8.314 J/K-mol)

Answer 6

Did anyone ever figure out how to do this?