You've reached the end of your free preview.
Want to read the whole page?
Unformatted text preview: 5/7/2020 Coffee Problem Page loaded on Thursday 7. May 2020 17:34:29
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 75.0°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
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 ºC).
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.
Experimental part: DONE
How will you prepare the beverage?
add 200 mL of coffee in an insulated beaker and raise the temperature to 85 C. then add 29.4 mL of milk that has been heated to 7 C. this will bring down the overall
temperature to 75 C.
How much milk will you add?
Well done! You did a good job!
You may now print this page to turn in with your assignment. chemcollective.org/activities/autograded/115 1/1 ...
View Full Document