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 250ml of house coffee at precisely 95°C. He then adds enough milk at 4°C to drop the temperature of the coffee 90°C. Calculate the amount of milk (in ml) the professor must add to reach this temperature. Show all your work.
Energy transfer
The flow of energy from one region to another region is referred to as energy transfer. Since energy is quantitative; it must be transferred to a body or a material to work or to heat the system.
Molar Specific Heat
Heat capacity is the amount of heat energy absorbed or released by a chemical substance per the change in temperature of that substance. The change in heat is also called enthalpy. The SI unit of heat capacity is Joules per Kelvin, which is (J K-1)
Thermal Properties of Matter
Thermal energy is described as one of the form of heat energy which flows from one body of higher temperature to the other with the lower temperature when these two bodies are placed in contact to each other. Heat is described as the form of energy which is transferred between the two systems or in between the systems and their surrounding by the virtue of difference in temperature. Calorimetry is that branch of science which helps in measuring the changes which are taking place in the heat energy of a given body.
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 250ml of house coffee at precisely 95°C. He then adds enough milk at 4°C to drop the temperature of the coffee 90°C.
- Calculate the amount of milk (in ml) the professor must add to reach this temperature. Show all your work.
Hint: the coffee us in an insulated travel mug, so no heat escapes.
(Assume coffee and milk have the same specific heat 4.186J/g °C. Assume that they also have the same density 1.0 g/ml.)
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