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meanmachine

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## Homework Statement

1kg of water that is initially at 90 degrees celsius with a quality of 10% occupies a spring loaded piston cylinder device. The device is now heated until the pressure rises to 800kPa and the temperature is 250 degrees c

Determine the total work done during this process, in KJ

## Homework Equations

The first law for closed systems

Q - W = ΔU

(h

_{2}-h

_{1}- u

_{2}- u

_{1}) = ΔU

## The Attempt at a Solution

State 1

Saturated mixture (90 degrees)

x = 0.1

H1 = 605.29 KJ/kg

U1 = 588.67 KJ/kg

State 2 - super heated vapour

h2 = 2950.4 KJ/kg

u2 = 2715.9 KJ/kg

therefore,

ΔU = (2950.4 - 605.29) - (2715.9 - 588.67) = 217.88 KJ

which is incorrect, can you assist me with this question?