A substance has a melting point of 20°C and a heat of fusion of 3.5 × 10⁴ J/kg.The boiling point is 150°C and the heat of vaporization is 7.0 × 10⁴ J/kg 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 given up by 0.50 kg of the substance when it is cooled from 170°C to 88°C,at a pressure of 1.0 atmosphere,is closest to

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Quizplus · Accepted Answer

The correct answer is A.The heat given up by the substance when it is cooled from 170°C to 88°C is:Q = m * c * (T2 - T1)where:m is the mass of the substance (0.50 kg)c is the specific heat of the substance in the appropriate phase (1000 J/(kg ∙ K) for the liquid phase)T2 is the initial temperature (170°C)T1 is the final temperature (88°C)Q = 0.50 kg * 1000 J/(kg ∙ K) * (170°C - 88°C)Q = 41 kJTherefore, the quantity of heat given up by the substance when it is cooled from 170°C to 88°C is closest to 41 kJ, which is choice A.

A Substance Has a Melting Point of 20°C and a Heat