A group of friends is cooking an exotic stew in a house in South Florida. One of the steps of the recipe is that they have to cool off the cooking mixture from 83.40 °C to 45.40 °C. The pot is too big to put it in a fridge for cooling down faster, the cooking mixture weighted 34.1 kg. Fortunately, one of the friends remembered thermochemistry and suggested that they put the pot in the small pool that is at the house to cool it off faster. The pool was not heated and its temperature before putting the pot with the stew was 19.56 °C. Given that the mass of water in the pool was 4,669.5 kg, and the specific heat capacity of the pool is 4.30 J/(g°C) and that of the cooking mixture is 4.20 J/(g°C), what is the final temperature of the pool after the cooking mixture cooled down to the temperature needed by the recipe?

A group of friends is cooking an exotic stew in a house in South Florida. One of the steps of the recipe is that they have to cool off the cooking mixture from 83.40 °C to 45.40 °C. The pot is too big to put it in a fridge for cooling down faster, the cooking mixture weighted 34.1 kg. Fortunately, one of the friends remembered thermochemistry and suggested that they put the pot in the small pool that is at the house to cool it off faster. The pool was not heated and its temperature before putting the pot with the stew was 19.56 °C. Given that the mass of water in the pool was 4,669.5 kg, and the specific heat capacity of the pool is 4.30 J/(g°C) and that of the cooking mixture is 4.20 J/(g°C), what is the final temperature of the pool after the cooking mixture cooled down to the temperature needed by the recipe?

Chemistry for Engineering Students

4th Edition

ISBN:9781337398909

Author:Lawrence S. Brown, Tom Holme

Publisher:Lawrence S. Brown, Tom Holme

Chapter9: Energy And Chemistry

Section: Chapter Questions

Problem 9.100PAE: 9.100 Two baking sheets are made of different metals. You purchase both and bake a dozen cookies on...

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The enthalpy of vaporization for water is 40.65 kJ mol-1. As a design engineer for a project in a desert climate, you are exploring the option of using evaporative cooling. (a) If the air has an average volumetric heat capacity of 0.00130 J cm-3 K-1, what is the minimum mass of water that would need to evaporate in order to cool a 5 m? 5 m room with a 3 m ceiling by 5°F using this method? (b) Is this a spontaneous or nonspontaneous process?
When 1.000 g of ethylene glycol, C2H6O2, is burned at 25C and 1.00 atmosphere pressure, H2O(l) and CO2(g) are formed with the evolution of 19.18 kJ of heat. a Calculate the molar enthalpy of formation of ethylene glycol. (It will be necessary to use data from Appendix C.) b Gf of ethylene glycol is 322.5 kJ/mol. What is G for the combustion of 1 mol ethylene glycol? c What is S for the combustion of 1 mol ethylene glycol?
When 1.000 g of gaseous butane, C4H10, is burned at 25C and 1.00 atm pressure, H2O(l) and CO2(g) are formed with the evolution of 49.50 kJ of heat. a Calculate the molar enthalpy of formation of butane. (Use enthalpy of formation data for H2O and CO2.) b Gf of butane is 17.2 kJ/mol. What is G for the combustion of 1 mol butane? c From a and b, calculate S for the combustion of 1 mol butane.
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9.100 Two baking sheets are made of different metals. You purchase both and bake a dozen cookies on each sheet at the same time in your oven. You observe that after 9 minutes, the cookies on one sheet are slightly burned on the bottom, whereas those on the other sheet are fine. (You are curious and you vary the conditions so you know the result is not caused by the oven.) (a) How can you use this observation to infer something about the specific heat of the materials in the baking sheets? (b) What is themathematical reasoning (equation) that you need to support your conclusion?
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