Calorimetry.....

Question

You order a 16 oz glass of tea (where the mass of Tea is 474 grams) from a local restaurant. The tea is freshly brewed and has an initial temperature of 22.13 °C. You add ice to cool it. If the heat of fusion of ice is 6.020 ^kJ/_mol and each ice cube contains exactly 1 mol of water (assume the ice does not add anymore volume), how many ice cubes are necessary to cool the tea to 4.40 °C? The specific heat of the "tea" is 4.184 ^J/_g°C.

Answer 1

the key to answering this question is to recognize that all the heat lost by the tea is gained by the ice cube in order to melt it.

heat lost by the tea= q=(474g)(4.184)(17.73)= 3.5162E4 J

heat gained by ice is therefore also 3.5162E4J=35.1624 kJ

35.1624kJ=(6.02)(x mol)

x=5.841 moles

5.841 ice cubes ( or 6 if only whole numbers allowed)