VLAB3 -certificate.pdf - Coffee Problem Page loaded on...

Unformatted text preview: 5/7/2020 Coffee Problem Page loaded on Thursday 7. May 2020 17:34:29 Name:__________________________ 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 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 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 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? 29.4mL. 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