Question

calculate kinetic energy of 5 moles of an ideal gas at 27°C

Answer 1

K.E can be calculated; K.E = [(3 x 8.3145 J/mol.K x (127 + 273)K] / 2 x 4 mol = 1247.175 Joules. The kinetic energy of 4 moles of N2 at 400 K (at 127 C) is 1.25 kJ (1247.175 J). No of moles given = 5 moles of nitrogen. Therefore n=5.

Answer 2

Kinetic energy of the ideal gas can be calculated as 

Kinetic energy = {3*n*R*T} / 2

where, 

n = number of moles

R = gas constant

T = temperature in kelvin

We have above is, n = 5 moles of N

R = 8/314, 

and T = 27 + 273 (to convert celsius to kelvin, add 273)=300. 

Kinetic energy = {3*5*8.314*300} / 2

= 18,706.05 joules or 18.706 kj