Exam 2 Review
Supplemental Instruction
Iowa State University / Leader: / Emily
Course: / Chem 177
Instructor: / Appy
Date: / 3/6/16
  1. Determine the oxidation state of nitrogen in each of the following:
  2. NH3
  3. N2O4
  4. NaNO3
  1. Using the activity series, write balanced chemical equations for the following reactions.
  2. Mg is added to a solution of silver nitrate
  1. Hydrogen gas is passed over a sample of zinc oxide
  1. How many milliliters of solution would contain 45.0 g sucrose () is the molarity were 4.09 M?
  1. What is the molarity of a solution of H3PO4 is 50.00 ml of it is titrated with 25.86 ml of 0.1201 M NaOH? Assume that all three hydrogens in H3PO4 react with NaOH.
  1. How many K+ ions are there in 200.0 mL of a 0.20 M K2SO4 solution?
  1. Balance the following equation and give the net ionic equation:
  1. Which of the following sets of quantum numbers is invalid?
  1. Which one of the following sets of quantum numbers corresponds to a 6p electron?
  1. A mercury atom is initially in its lowest possible (or ground state) energy level. The atom absorbs a photon with a wavelength of 185 nm, and then emits a photon with a frequency of 6.88 x 1014 Hz. At the end of this series of transitions, the atom will still be in an energy level above ground state. Draw an energy level diagram for this process, and find the energy of this resulting excited state, assuming we assign a value of E = 0 to the ground state.
  1. Which atomic orbital has 3 nodal surfaces?
  2. 3s and 3p
  3. b. 3s and 4s
  4. c. 4s and 4p
  5. d. All p atomic orbitals
  1. What is the frequency of yellow light with wavelength of 595 nm?
  1. What volume of 1.57 M HCl would react completely with 22.5 g Mg?
  1. A 0.500 g sample of naphthalene (C10H8) is burned in a bomb calorimeter containing 650 grams of water at an initial temperature of 20.00ºC. After the reaction, the final temperature of the water is 26.4ºC. The heat capacity of the calorimeter is 420 J/ºC. Using this data, calculate the heat of combustion of naphthalene in kJ/mol.
  1. Determine the final temperature when 10.0 g of aluminum at 130.0 °C mixes with 200.0 grams of water at 25.0 °C. The specific heat of aluminum is 0.901 J/g °C. (Coffee cup calorimeter problem.)
  1. Find the ΔH°rxn for C2H6(g) + 7/2 O2(g)  2 CO2(g) + 3 H2O(g)

ΔH°f C2H6(g) = -84.7 kJ/mol

ΔH°f CO2(g) = -393.5 kJ/mol

ΔH°f H2O(g) = -241.8 kJ/mol

  1. A piece of copper metal of mass 6.22 kg is heated from 20.5 °C to 324.3 °C. Calculate the heat absorbed by the metal. Specific heat is 0.386J/g °C.
  1. If 3.4 kJ of heat flows out of the system while 4.8 kJ of work is done by the system on the surroundings, what is the internal energy?
  1. Given the following reactions,

2 S(s) + 3 O2 (g)  2 SO3(g)ΔH = -790 kJ

S(s) + O2(g)  SO2 (g)ΔH = -297 kJ

What is ΔH° for the reaction 2 SO2(g) + O2(g)  2 SO3(g)?

  1. Write the formation reaction for CaCO3.
  1. Silane, SiH4, burns according to the reaction, SiH4 + 2 O2 SiO2 + 2 H2O, with

ΔH° = -1429 kJ. How much energy is released if 15.7 g of silane is burned?

  1. The retina of a “predator” eye can function in nearly dark conditions, at 2.00*10-17J. For light of 685 nm wavelength, how many photons does this energy correspond to?
  1. Calculate the deBroglie wavelength (in nm) of a 3000 lb automobile traveling

at 55 mi/hr.

  1. Increasing the intensity of a light beam directed at matter results in which of the following?
  2. An increase in the number of electrons but does not change the energy of each electron
  3. An increase in the number of electrons excited and an increase in the energy of each electron
  4. An increase in the number of electrons excited and a decrease in the energy of each electron
  5. A decrease in the number of electrons excited and an increase in the energy of each electron

For the next two problems you are given the lead-acid battery reaction:

Pb + PbO2+ H2SO42PbSO4+ 2H2O

  1. Which species is oxidized during battery discharge?
  2. H2SO4
  3. PbO2
  4. Pb
  5. H2O
  1. Which species functions as an electrolyte?
  2. H2SO4
  3. PbSO4
  4. H2O
  5. PbO2