First law of thermodynamics and work done

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SUMMARY

The discussion focuses on calculating the work done when converting two kilograms of water at 100°C to steam at 1 ATM. The correct approach involves using the formula W = PV, where P is the external pressure and V is the change in volume. The density of steam at 100°C is given as 0.598 kg/m³, which is crucial for determining the volume of steam produced. The integration method is unnecessary for this calculation, as the work can be derived directly from the pressure and volume relationship.

PREREQUISITES
  • Understanding of the First Law of Thermodynamics
  • Knowledge of pressure-volume work in thermodynamics
  • Familiarity with the properties of water and steam
  • Basic calculus for integration (optional, but not required for this problem)
NEXT STEPS
  • Calculate work done using the formula W = PV for phase changes
  • Explore the properties of steam and its density at various temperatures
  • Study the implications of the First Law of Thermodynamics in practical applications
  • Learn about phase transitions and their thermodynamic properties
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Students and professionals in physics, engineering, and thermodynamics who are interested in understanding work done during phase changes and applying the First Law of Thermodynamics in practical scenarios.

fly_bo1
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Two kilograms of water at 100oC is converted to steam at 1 ATM. Find the work done (in J). (The density of steam at 100oC is 0.598 kg/m3.)

a. 4.6 x 104
b. 3.4 x 104
c. 1.2 x 105
d. 2.1 x 104
e. 3.4 x 105

I'ved use the integration holding volume as a variable. However, I don't know why I am not getting the right answer.
 
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fly_bo1 said:
Two kilograms of water at 100oC is converted to steam at 1 ATM. Find the work done (in J). (The density of steam at 100oC is 0.598 kg/m3.)

a. 4.6 x 104
b. 3.4 x 104
c. 1.2 x 105
d. 2.1 x 104
e. 3.4 x 105

I'ved use the integration holding volume as a variable. However, I don't know why I am not getting the right answer.
You don't have to do an integration. Assume that the change in volume from water to steam occurs at 1 Atm external pressure and that the steam is created gradually. Pressure is constant, so W = \int PdV = PV (assume initial volume is 0).

AM

PS Welcome to PF, btw.
 

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