A sealed container has a volume of 0.020m^3 and contains 20g of molecular nitrogen (N2) which has a molecular?

Question

A sealed container has a volume of 0.020m^3 and contains 20g of molecular nitrogen (N2) which has a molecular mass of 28 u. The gas is at a temperature of 252 degrees celsius.

a) What is the pressure of the nitrogen gas?

b) If 500 Joules of heat are added to the gas, what is the change in its temperature?

Answer 1

(a) There are (20/28) moles of N2 molecules. According to the ideal gas law, we have:
P = nRT/V = (20/28)*0.08206*(252+273)/20 = 1.54 (atm)

(b) Cv = 5R/2 = 2.5*8.314 = 20.8 (J/K•mol) for a diatomic gas in a rigid container. Hence the change of its temperature is:
500/((20/28)*20.8) = 33.7K