1. 1.00 mole of a monatomic ideal gas is cooled from 573 K to 373 K.  What is the change in internal energy (U)? (Answer in Joules and with correct sign.)
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2. 1 kg of liquid water at 3.0 MPa and saturation is heated to 500 ºC holding pressure constant.  How much heat is required? (Answer in kJ.)
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3. 1.00 mole of an ideal, monatomic gas at 300 K and 1.00 bar is compressed to 20.0 bar . There is no heat exchange with the surroundings and the compression requires minimum amount of work. What is the final temperature of the gas? (Answer in K)