BTU 1. An ideal gas with R = 0.062- and Cy =0.158 b-2 ETU undergoes a three Ib"R process cycle in aclosed system. From the initial state of 20 psia and 570 R, the gas is compressed at constant temperature to 1/5 of its initial volume, process 1-2; it is then heated isochorically to state 3,process 2-3; and finally, it expands polytropically with index n= 1.5 back to its initial state, process 3-1. Determine the pressures, specific volumes and temperatures at cardinal points around the cycle and the cycle thermal efficiency.

Air as an ideal gas is contained in a piston/cylinder system constrained by a non-linear spring. Initially the gas in the cylinder is at 100 kPa, which is balanced by the atmospheric pressure outside of the cylinder (the weight of the piston is negligible). The force on the spring at the start is zero. The spring force is F=kx². k=600. kNt/m². The cross-sectional area of the piston is 1 m², the initial volume is 1 m³, and the initial temperature is 300 K. Heat is added until the volume of the gas has expanded to 1.5 m³. Find: (a) The work done by the gas on the face of the piston (kJ). (b) The final temperature (K). (c) The amount of heat added (kJ). Hint: This problem is easiest if you calculate the spring work and the atmospheric work separately. Air V₁=1.0 m³ Piston Area = 1.0 m² T₁=300 K P₁=100 kPa Atmospheric P on upper piston face= 100 kPa

Define the Energy change, Energy at final state, Energy at initial state?

A spring-loaded piston-cylinder device contains  of m=1kg carbon dioxide. Initially, the spring has no force on the piston and  , , . Heat is transferred to the gas, causing the piston to rise and to compress the spring. At the state 2,  , . The gas is an ideal gas. (7)How to calculate the total boundary work ?_____     A.     B.     C.     D.

i) Can water vapor at 442°C and 75 bar be modeled at ideal gas?