Thermochemistry and Heat Capacity
Create a solution of Coffee with a desired temperature

1. (3 pts) During the summer after your first year at Carnegie Mellon, you are lucky enough to get a job making coffee at Starbucks, but you tell your parents and friends that you have secured a lucrative position as a "java engineer." An eccentric chemistry professor (not mentioning any names) stops in every day and orders 250 ml of house coffee at precisely 95°C. He then adds enough milk at 4°C to drop the temperature of the coffee to 90°C.

    a) Calculate the amount of milk (in ml) the professor must add to reach this temperature. Show all your work, and circle the answer.

    b) Use the Virtual Lab to make the coffee/milk solution and verify the answer you calculated in a).

Hint: the coffee is in an insulated travel mug, so no heat escapes. To insulate a piece of glassware in Virtual Lab, Mac-users should hold down the command key while clicking on the beaker or flask; Windows users should right click on the beaker or flask. From the menu that appears choose "Thermal Properties." Check the box labeled "insulated from surroundings." The temperature of the solution in that beaker or flask will remain constant.

(Assume coffee and milk have the same specific heat capacity: 4.186 J/g °C. Assume that they also have the same density: 1.0 g/ml.)*