When 0.455 g of anthracene, C14H10, is combusted in a bomb calorimeter that has a water jacket containing 500. g of water, the temperature of the water increases by 8.63C.
Assuming that the specific heat of water is 4.18 J/(g C), and that the heat absorption by the calorimeter is negligible, estimate the enthalpy of combustion per mole of anthracene.
A) +39.7 kJ/mol
B) -39.7 kJ/mol
C) -7070 kJ/mol
D) -8120 kJ/mol
Question 2
A 255 mL round-bottom flask is weighed and found to have a mass of 114.85 g. A few milliliters of an easily vaporized liquid are added to the flask and the flask is immersed in a boiling water bath.
All of the liquid vaporizes at the boiling temperature of water, filling the flask with vapor. When all of the liquid has vaporized, the flask is removed from the bath, cooled, dried, and reweighed. The new mass of the flask and the condensed vapor is 115.23 g. Which of the following compounds could the liquid be? (Assume the ambient pressure is 1 atm.) A) C4H10
B) C3H7OH
C) C2H6
D) C2H5OH
E) C4H9OH
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A thimble of water contains 4.0 x 1021 molecules. The number of moles of H2O is: