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Coffee
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 200ml of Sumatran coffee at precisely 60.0°C. You then need to add enough milk at 7.00°C to drop the temperature of the
coffee, initially at 85.0°C, to the ordered temperature.
Calculate the amount of milk (in ml) you must add to reach this temperature. Show all your work in the provided spaces.
In order to simplify the calculations, you will start by assuming that milk and coffee have the specific heat and density as if water. In the following
parts, you will remove these simplifications. Solve now this problem assuming the density is 1.000 g/ml for milk and coffee and their specific heat
capacity is 4.184 J//g °C).
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 command-click
(or open-apple click) 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.
Use the Virtual Lab to verify your answer,
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Coffee
Stockroom
Workbench 1