## Doggiebounce Group Title 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 one year ago one year ago

1. chmvijay

do you know equation for average kinetic energy

2. .Sam.

From kinetic theory, $E_K=\frac{1}{2}m<c^2>=\frac{3}{2}k_BT$ --------------------------------------- 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

3. .Sam.

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

4. chmvijay

ur right i is 3KT/2

5. .Sam.

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

6. Pumpkin890

Did anyone ever figure out how to do this?