Question

I'm confused on this problem
A gaseous mixture inside a rigid steel vessel contains 75% CO2 and 25% H2O by volume at 175 degrees C and 225 kPa. The mixture is then cooled to 0 degrees C, thereby condensing the water vapor. What is the pressure of the CO2 at 0 degrees C? (assume that there is no water vapor present after condensation)
Please help me

Answer 1

X_CO2 = 0.75
X_H2O = 0.25
P_CO2 = X_CO2*P_total
P_H2O = X_H2O*P_total

After the water condenses, the only gas left in the container is CO2 and it has changed T from 175 C to 0 C. Use
(P1/T1) = (P2/T2) to calculate the new pressure at the new T.
Post your work if you get stuck.