A 7.50 g marshmallow is placed in a calorimeter and burned in excess oxygen.The temperature increases by 4.69$\degree$C.The calorimeter has a heat capacity of 22.3 kJ/$\degree$C.What is the approximate food value of marshmallows in Cal/g? (1 Cal = 4.184 kJ)

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Quizplus · Accepted Answer

The heat absorbed by the calorimeter is calculated using the formula: Heat = Heat capacity × Temperature change = 22.3 kJ/°C × 4.69°C = 104.587 kJ. To find the food value in Cal/g, convert kJ to Cal (1 Cal = 4.184 kJ), so 104.587 kJ = 25 Cal. Then, divide by the mass of the marshmallow: 25 Cal / 7.50 g = 3.33 Cal/g.

A 750 G Marshmallow Is Placed in a Calorimeter and Burned