Final Exam Review #3
Supplemental Instruction
Iowa State University / Leader: / Allison
Course: / Chem 163
Instructor: / Dr. Appy
Date: / 12/14/14
  1. Define and state the ΔErxn for each:
  2. Exothermic:
  3. Endothermic:
  4. Use the chart to answer the following questions:

Reaction / Energy of Reactants (kJ/mol) / Energy of Products (kJ/mol) / Energy of Transition State (kJ/mol)
1 / 50 / 60 / 70
2 / 20 / 10 / 90
3 / 10 / 20 / 90
  1. Indicate whether the reactions are endothermic or exothermic.
  1. Determine the value of ΔErxn.
  1. Determine the value of Ea.
  1. In the reaction of X + Y --> Z, the energy of the reactants is 60 kJ/mol, and the energy of the products is 90 kJ/mol. The energy of the transition state is 130 kJ/mol.
  2. Is the reaction endothermic or exothermic?
  3. What is the Erxn?
  4. What is the Ea?
  5. Catalysts speed up reactions by:
  6. Providing an alternative mechanism for a reaction
  7. Lowering the Ea for the reaction
  8. Remaining active throughout the chemical reaction
  9. All of the above are correct.
  1. The slow step in the mechanism for the production of NO2F from NO2 and F2 is 2NO2 + F2 --> NO2F + F. Write the predicted rate law for the reaction.
  1. Write the equilibrium constant expression for the reaction

H2 (g) + I2 (g) <--> 2 HI (g)

  1. Write the Keq for the following reaction and solve for the Keq with the following concentration at equilibrium
  2. CH4 + 2O2 -> CO2 +2 H2O

0.234 0.20 0.378 0.209

  1. Using Le Chatelier’s principle:
  1. Concentration
  2. If we increase the concentration of the reactants, which way will the equilibrium switch?
  1. If we increase the concentration of the products, which way will the equilibrium switch?
  1. Will the Keq change?
  1. Temperature
  2. Which way will the equilibrium switch if we increase the temperature?
  1. If we decrease the temperature?
  2. Will the Keq change?
  1. Pressure
  2. If we increase the pressure which way will the equilibrium switch?
  3. If we decrease the pressure?
  4. Will the Keq change?
  1. Describe the difference between electrolytes and nonelectrolytes:
  2. Answer the following questions:
  3. Is the compound H2SO4 molecular or ionic?
  1. How did you decide on your answer to part (a)?
  1. Based on your answer to part (a), would you call H2SO4 an electrolyte or a nonelectrolye?
  1. An aqueous solution of H2SO4 causes a light bulb to light. What does this tell you about H2SO4?
  1. What is the difference between a strong electrolyte and a weak electrolyte?
  1. What is the difference between a strong acid and a weak acid?
  1. Brønsted-Lowry definition of an acid:
  1. Brønsted-Lowry definition of a base:
  1. In the reaction NH3 + PH3 --> NH2- + PH4+ which reactant is the Brønsted-Lowry acid and which is the base?
  1. Write the formula of the salt formed from the combination of H3PO4 and LiOH.
  1. Calculate the [OH-] in a solution in which [H3O+] = 2.3 x 10^-4

For Hydrogen:

Useful Equations and Constants:

1 mi = 5280 ft

1 in = 2.54 cm

1 mL = 1 cm3

d = m/V

K = ºC + 273.15 ºF = 32 + (9/5)ºC ºC = (5/9)(ºF – 32)

q = mCsΔT

avg. atomic mass = m1f1 + m2f2 + …..

E = hc/λ

c = 3.00 x 108 m/s

h = 6.626 x 10-34 J*s

1 eV = 1.602 x 10-19 J

1 m = 109 nm

F = kq1q2/r2

1 mole = 6.022 x 1023 things

% yield = (actual yield)/(theoretical yield) x 100%

PV = nRT

PiVi/(niTi) = PfVf/(nfTf)

MM = mRT/(PV)

MiVi = MfVf

R = 0.0821 L*atm/(mol*K)

STP = 0 °C and 1 atm

K = °C + 273.15

ΔTf,b = Kf,b x moles of solute / (Kg solvent)

P = F/A

Kw = [H3O+][[OH-] = 10-14

pH = -log[H3O+]