Chemistry - Thermochemistry Question with Solution | TestHub
An intimate mixture of carbon monoxide gas and the theoretical amount of air at 27°C and a total pressure of 1 atm, is exposed in a closed rigid vessel. If the process occurs under adiabatic condition, then using the following data, answer the following questions. Take R = 2 cal/K-mol and 27°C = 300 K.
Given: (i) CP,m(N2) = 7.0 cal/K-mol (ii) CP,m(CO2) = 9.5 cal/K-mol (iii) CO(g) + 1/2O2(g) → CO2(g), ΔH = -34.0 kcal, independent of temperature (iv) Air contains 20% O2 and 80% N2 by volume
If at initial temperature T1, H1 is the enthalpy of the system and at the final higher temperature T2, H2 is the enthalpy, then
Options:
Answer:
Solution:
The vessel is rigid and adiabatic, so ΔU = 0. Then ΔH = ΔU + Δ(PV) = V(P2 - P1) since V is fixed. The pressure rises from 1 atm to about 6.4 atm, so ΔH > 0 and H1 < H2. This is option (a).
