208k views
4 votes
One cubic meter of argon is taken from 1 bar and 25°C to 10 bar and 300°C by each of

the following two-step paths. For each path, compute Q, W, ΔU, and ΔH for each step
and for the overall process. Assume mechanical reversibility and treat argon as an
ideal gas with CP = (5/2)R and CV = (3/2)R.
(a) Isothermal compression followed by isobaric heating.
(b) Adiabatic compression followed by isobaric heating or cooling.
(c) Adiabatic compression followed by isochoric heating or cooling.
(d) Adiabatic compression followed by isothermal compression or expansion

User OLen
by
8.5k points

1 Answer

3 votes

Final answer:

In each of the given two-step paths, the argon gas undergoes different thermodynamic processes. The calculations for Q, W, ΔU, and ΔH are explained for each step and the overall process for each path.

Step-by-step explanation:

In each of the given two-step paths, the argon gas undergoes different thermodynamic processes. Let's calculate Q, W, ΔU, and ΔH for each step and the overall process for each path:

(a) Isothermal compression followed by isobaric heating:

- Step 1: Isothermal compression (Q = 0, W < 0, ΔU < 0, ΔH < 0)

- Step 2: Isobaric heating (Q > 0, W > 0, ΔU > 0, ΔH > 0)

- Overall process: Q = Q1 + Q2, W = W1 + W2, ΔU = ΔU1 + ΔU2, ΔH = ΔH1 + ΔH2

(b) Adiabatic compression followed by isobaric heating or cooling:

- Step 1: Adiabatic compression (Q = 0, W < 0, ΔU < 0, ΔH < 0)

- Step 2: Isobaric heating or cooling (Q ≠ 0, W ≠ 0, ΔU ≠ 0, ΔH ≠ 0)

- Overall process: Q = Q1 + Q2, W = W1 + W2, ΔU = ΔU1 + ΔU2, ΔH = ΔH1 + ΔH2

(c) Adiabatic compression followed by isochoric heating or cooling:

- Step 1: Adiabatic compression (Q = 0, W < 0, ΔU < 0, ΔH < 0)

- Step 2: Isochoric heating or cooling (Q ≠ 0, W ≠ 0, ΔU ≠ 0, ΔH ≠ 0)

- Overall process: Q = Q1 + Q2, W = W1 + W2, ΔU = ΔU1 + ΔU2, ΔH = ΔH1 + ΔH2

(d) Adiabatic compression followed by isothermal compression or expansion:

- Step 1: Adiabatic compression (Q = 0, W < 0, ΔU < 0, ΔH < 0)

- Step 2: Isothermal compression or expansion (Q = 0, W ≠ 0, ΔU ≠ 0, ΔH ≠ 0)

- Overall process: Q = Q1 + Q2, W = W1 + W2, ΔU = ΔU1 + ΔU2, ΔH = ΔH1 + ΔH2

User Duce
by
7.4k points