Final answer:
To find the final temperature and pressure of the steam during the power stroke of a steam engine, you can use the Ideal Gas Law. As the process is adiabatic, with no heat transfer, you can set the change in internal energy to 0 and solve for the final temperature.
Step-by-step explanation:
During the power stroke of a steam engine, the superheated water vapor undergoes an adiabatic expansion until it reaches a saturated vapor state. To find the final temperature and pressure of the steam, we can use the Ideal Gas Law. The Ideal Gas Law states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Since the process is adiabatic, Q = 0. This means that no heat is transferred to or from the system. Therefore, the change in internal energy of the steam is also 0. We can express the change in internal energy as ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat transfer, and W is the work done by the steam.
By setting ΔU = 0 and solving for T2, we can find the final temperature of the steam. By plugging in the values for P1, V1, and T1, we can find the initial number of moles of steam, n1. We can then use the ideal gas law to find the final number of moles of steam, n2, by plugging in the values for P2, V2, and T2. Finally, we can use the ideal gas law again to find the final pressure, P2, by solving for P2 and plugging in the Known values for V2, n2, and T2.