An ideal gas initially at atmospheric pressure and a tempera

An ideal gas, initially at atmospheric pressure and a temperature of 324.0 K, is compressed from a volume of 1.50 L to 0.75 L A)What is the change of entropy of the gas if this process is performed isothermally? J/K What is the change of entropy of the gas if this process is performed adiabatically? J/k

Solution

For isothermal process change in entropy

s = nRln(V/V₀)

initial volume V = 1.5L = 1.5e-3 m³

initial pressure P = 1atm = 101e+3 N

initial temp T = 324 K

PV=nRT

101e+3*1.5e-3 = nR*324

nR = 101*1.5/324 = 0.468

s = 0.468ln(0.75/1.5) = -0.324

For an adiabatic process no heat is given to the system nor delivered by the system. hence

s = 0