Question

The molar heat capacity for carbon monoxide at constant volume is CV,m = 20.17 J/(K·mol). A 3.00-L fixed-volume flask contains CO(g) at a pressure of 8.00 kPa and a temperature of 25.0 °C. Assuming that carbon monoxide acts as an ideal gas and that its heat capacity is constant over the given temperature range, calculate the change in entropy for the gas when it is heated to 800.0 °C.
THIS IS FOR MY HIGHSCHOOL, BUT IS MAINLY COLLEGE STUFF PLEASE HELP ME A BIT ;-;

Answer 1

ΔS = 0.250 J·K^(-1)

Step 1. Calculate the moles of CO

From the Ideal Gas Law,

n = (pV)/(RT) = (8.00 kPa × 3.00 L)/(8.314 kPa·L·K^(-1)·mol^(-1) × 298.15 K)

= 0.009 682 mol  

ΔS = nC_Vln(T_2/T1)

= 0.0096 82 mol × 20.17 J·K^(-1)mol^(-1) ln(1073.15 K/298.15 K)

=  0.1953 J·K^(-1) × ln3.599 = 0.250 J·K^(-1)