Question

In: Chemistry

If your air conditioner is more than several years old, it may use the chlorofluorocarbon CCl2F2...

If your air conditioner is more than several years old, it may use the chlorofluorocarbon CCl2F2 as the heat transfer fluid. (CFCs such as this are being replaced as rapidly as possible by substances less harmful to the environment.) The normal boiling point of CCl2F2 is -29.8°C, and the enthalpy of vaporization is 20.11 kJ/mol. The gas and the liquid have specific heats of 117.2 J/mol·K and 72.3 J/mol·K, respectively. How much heat is evolved when 50.0 g of CCl2F2 is cooled from +40°C to -40°C?

Solutions

Expert Solution

Moles of CCl2F2 = mass / Molar mass = 50 g / 120.9 g/mol = 0.413565 mol

Heat released when cooling CCl2F2 form 40 C to - 29.8 C = specific heat of gas x moles x change in temp

        = 117.2 J/molK x 0.413565 mol x (40- ( -29.8)   = 3383.2 J = 3.383 KJ

Heat released for phase transformation of gas to liquid at - 29.8 C = enthalphy fo vaporisation x moles

             = 20.11 KJ/mol x 0.413565 = 8.317 KJ

Heat released in cooling liquid CCL2F2 from - 29.8 to -40 C = specific heat x moles x temp change

          = 72.3 J/molK x 0.413565 mol x (-29.8 - ( -40)   = 305 J = 0.305 KJ

Total heat released = sum of three process = 3.383 + 8.317 + 0.305 = 12 KJ


Related Solutions

Arvo Lake, a retired seventy-one-year-old man, bought an air conditioner in May 2018. The unit was...
Arvo Lake, a retired seventy-one-year-old man, bought an air conditioner in May 2018. The unit was installed and operated according to the manufacturer's instructions. Unbeknownst to Lake, the unit contained a hole in the refrigeration system that allowed Freon, the coolant, to escape from the unit. By August, the unit had ceased cooling, and Lake's residence reached a temperature of at least 96 degrees Fahrenheit. The heat caused Lake to suffer from hyperthermia, which caused circulatory failure and death. The...
Search for an article online that is no more than 10 years old where there was...
Search for an article online that is no more than 10 years old where there was a legal or ethical issue involding a nurse. In a few sentences tell me what you thought about the incident.
Suppose that your air conditioner fails on Sunday at midnight (t0 = 0), and you cannot...
Suppose that your air conditioner fails on Sunday at midnight (t0 = 0), and you cannot afford to have it repaired until payday at the end of the month. Assume that the outside temperature varies according to the function. A(t)= 80 − 5 cos(π/12t)-5√3sin(π/12t) and that your inside temperature, u(t) obeys Newton’s law of cooling and is governed by the differential equation du/dt=−0.2(u − A(t)) (a) If your indoor temperature when the air conditioner failed was 70◦F, determine the dynamics...
Suppose that your air conditioner fails on Sunday at midnight (t0 = 0), and you cannot...
Suppose that your air conditioner fails on Sunday at midnight (t0 = 0), and you cannot afford to have it repaired until payday at the end of the month. Assume that the outside temperature varies according to the function A(t) = 80 5 cos(π/12)-5√3sin(π/12t) and that your inside temperature, u(t) obeys Newton’s law of cooling and is governed by the differential equation du/dt= -0.2(u-A(t)) (a) If your indoor temperature when the air conditioner failed was 70◦F , determine the dynamics...
ABC Company sells two types of air conditioner systems – one for commercial use and one...
ABC Company sells two types of air conditioner systems – one for commercial use and one for residential use. The following inventory data was collected by the staff in the office of the controller for the first month of the company’s fiscal year. Commercial Air Conditioner Systems: Qty Unit Cost Total Cost Unit Selling Price Total Selling Price 12/31/2017 Balance             600             800      480,000 1/3/2018 Purchase             600             900      540,000 1/12/2018 Purchase             300             950...
Find an accounting-related fraud court case that is no more than 2 years old and then...
Find an accounting-related fraud court case that is no more than 2 years old and then find an accounting-related fraud court case that is over 10 years old. Give a brief summary of both court cases. Compare and contrast the 2 court cases. Discuss if you think the level of sophistication in committing fraud has changed over the years. Who is committing the crime and how? What impact, if any, will the changes you found have on the auditor and/or...
Your company operates a bulldozer that is several years old, and needs to be repaired frequently....
Your company operates a bulldozer that is several years old, and needs to be repaired frequently. You estimate that you can run it for only two more years, and that if you do, it will generate cash flows of $5,000 next year and $5,000 in the year after that. If you trade in the old bulldozer (forgoing these cashflows) and purchase a new one for $50,000 (the balance owing after the trade in allowance), you estimate the new one will...
Use the following words to fill in the blanks, some may be used more than once...
Use the following words to fill in the blanks, some may be used more than once or not at all: Increase; Decrease; Greater Than; Less Than; Equal; System; Effusion; Enthalpy; Diffusion; Entropy; Mass; Volume; Density; Heat; Temperature; State; Calorimeter; Specific Heat; Gas; Extensive; Intensive, surrounding A. Calorimetry is possible because all the energy which leaves the _________ is absorbed by the _________, and vice versa B. When volume is held constant, the term for work goes to zero, which allows...
WRITE IN JAVA PLEASE~ A string may use more than one type of delimiter to bracket...
WRITE IN JAVA PLEASE~ A string may use more than one type of delimiter to bracket information into "blocks". The primary ways to divide things up into block is by the braces { } , parentheses ( ), and brackets [ ] as delimiters. A string is considered properly delimited if each right delimiter ] } or )( is matched with a preceding left delimiter { [ ( of the same type in such a way that either the resulting...
JAVA question A string may use more than one type of delimiter to bracket information into...
JAVA question A string may use more than one type of delimiter to bracket information into "blocks". The primary ways to divide things up into block is by the braces { } , parentheses ( ), and brackets [ ] as delimiters. A string is considered properly delimited if each right delimiter ] } or )( is matched with a preceding left delimiter { [ ( of the same type in such a way that either the resulting blocks of...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT