Chapter 6, Problem 6.8P

Water contained in a closed, rigid tank, initially at 100 lb;/in², 800°F, is cooled to a final state where the pressure is 50 lb;/in?. Determine the quality at the final state and the change in specific entropy, in Btu/lb-°R, for the process.

One-tenth kmol of carbon monoxide (CO) in a piston- cylinder assembly undergoes a process from p1 = 150 kPa, T1 = 300 K to p2 = 500 kPa, T2 = 370 K. For the process, W = -300 kJ. Employing the ideal gas model, determine: (a) the heat transfer, in kJ. (b) the change in entropy, in kJ/K.

One kg of an ideal gas (gas constant R = 287 J/kg.K) undergoes an irreversible process from state-1 (1 bar, 300 K) to state -2 (2 bar, 300 K). The change in specific entropy (52 - s1) of the gas (in J/kg. K) in the process is

1. As shown in the figure below, Refrigerant 134a enters a condenser operating at steady state at 70 lbf/in2, 160 °F and is condensed to saturated liquid at 60 lbf/in on the outside of tubes through which cooling water flows. In passing through the tubes, the cooling water increases in temperature by 20 'F and experiences no significant pressure drop. Cooling water can be modeled as incompressible with v-0.0161 ft'/lb and c = 1 Btu/lb R. The mass flow rate of the refrigerant is 3100 lb/h. Neglecting kinetic and potential energy effects and ignoring heat transfer from the outside of the condenser, determine: (a) The volumetric flow rate of the entering cooling water, in gal/min (b) The rate of heat transfer, in Btu/h, to the cooling water from the condensing refrigerant (5 points) Refrigerant 134a P= 70 in. T= 160 F 3100 heh 7,-7,-20F-20R Reirigerant 134a [P-60 lbin V Saturated liquid

Determine the change in specific entropy, in kJ/kg K, of CO2 as an ideal gas undergoing a process from T, = 300 K, p, = 1 bar to T2 = 1420 K. P2 = 5 bar. Additional information g°= 1.70203 KJKG K °2 = 3.37901 kJikg K 1.215 kJ/kg. °C 1.215 kJkg. K 0 1.190 kJ/kg K O 1.373 kJ/kg K

C6 2.

A non-flow reversible process occurs for which pressure and volume are correlated by the expression p = (V2 + 6/V) where p is in bar and V is in m³. What amount of work will be done when volume changes from 3 to 5 m³?

Argon (molar mass 40 kg/kmol) compresses reversibly in an adiabatic system from 5 bar, 25 0C to a volume of 0.2 m3. If the initial volume occupied was 0.9 m3, calculate the final pressure in bar to 2 decimal places. Assume nitrogen to be a perfect gas and take cv = 0.3122 k J / k g K.

1. thermodynamics