7.7mol of helium are in a 16L cylinder. The pressure gauge on the cylinder reads 65psi. What are (a) the temperature of the gas in Celsius and (b) the average kinetic energy of a helium atom?

Question

Part A:
so this is what i did
T=PV/nR and C=T-273

P=65psi=4.481592e^5Pa
V=16L=.016m^3
n=7.7mole
R=8.31
so T=.1663155895
C=-272.8336844
this is incorrect
I'm waiting for part a to work on part b

Answer 1

I will assume that the 65 psi is the absolute pressure (psia), although most pressure gauges that read that high would be reading gauge pressure. 65 psia is 4.42 atm

PV/nT = R = 0.08205 atm-liter/(mole*K)

T = PV/(nR) = 4.42*16/(7.7*.08205) = 112 K

The average kinetic energy per atom is (3/2)kT. The molecular weight does not matter. k is Boltzmann's constant, 1.38*10^-23 J/K

Answer 2

I appreciate your help but this isn't working out