General Chemistry IName _________________
CHM 121-004Date __________________
Part B (Comprehensive Questions: 20 points)
Show detailed approach in the enclosed space to receive full credit for each answer..
36.Calculate the standard enthalpy change for the given reaction.
PbS(s) + 4H2O2(aq) PbSO4(s) + 4H2O(l)
(Obtain ΔHof (kJ/mol) values for the substances from the textbook — Pg. 250 and Appendix C, A-8 )(4 points)
37. The sugar, Glucose, C6H12O6, is burned completely in oxygen in a calorimeter.
C6H12O6(s) + 6O2(g) 6CO2(g) + 6H2O(l)
Burning a 0.560 g sample of glucose caused the temperature to rise from 22.00° C to 22.64° C. The heat capacity of the calorimeter and its contents is 15.8kJ/°C. Calculate ΔH for the combustion reaction per mole of Glucose.
38.Calculate the energy of the emitted photon as well as the wavelength and frequency of electromagnetic radiation emitted from the hydrogen atom when the electron undergoes the transition from n = 5 to n = 1. In what region of the spectrum does this line occur?(4 points)
39a.Give the electron configuration of the ground state of the bromine, Br atom. Give the noble-gas configuration and pseudo-noble-gas core of the ground state bromine atom. How many valence electrons are present in the ground-state electron configuration of the bromine atom?.
( 2 points)
39b. Ethanol, C2H5OH, is mixed with gasoline and sold as gasohol. Use the following to calculate the grams of ethanol needed to provide 388 kJ of heat.
C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(g) ; H = -1235 kJ.(2 points)
40a.What is the de Broglie wavelength of an oxygen molecule, O2, traveling at 521 m/s? Is the wavelength much smaller or much larger than the diameter of an atom (on the order of 100 pm). (Hint: Calculate and apply the mass of an oxygen molecule).(2 points)
40b.State which of the following sets of quantum numbers would be permissible and which would be impossible for an electron in an atom. If not permissible, then explain your answer.(2 points)
n = 0, l = 0, ml= 0, ms= +1/2
n = 2, l = 1, ml= -1, ms= +1/2