Phase Changes: a Substance Has a Melting Point of 20°C

question 34

Multiple Choice

Phase changes: A substance has a melting point of 20°C and a heat of fusion of 3.9 × J/kg. The boiling point is and the heat of vaporization is at a pressure of 1.0 atm. The specific heats for the solid, liquid, and gaseous phases are 600 J/(kg ∙ K) , 1000 J/(kg∙K) , and 400 J/(kg ∙ K) , respectively. The quantity of heat required to raise the temperature of of the substance from to at a pressure of 1.0 atm, is closest to

• A) 620 kJ.
• B) 470 kJ.
• C) 560 kJ.
• D) 210 kJ.
• E) 770 kJ.

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