Second Review

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  1. Stoichiometry
  2. Explain how mass and atoms are conserved in a balanced chemical reaction but moles are not necessarily conserved.
  3. Balance the following equations:
    1. H2 + O2 --> H2O
    2. C2H2 + O2 --> CO2 + H2O
    3. CaCO3 + H3PO4 --> Ca3(PO4)2 + CO2 + H2O
  4. 4 Al (s) + 3 O2 (g) --> 2 Al2O3 (s)
    1. How many moles of aluminum oxide are formed from 3.7 moles of oxygen?
    2. How many grams of oxygen are needed to react completely with 22.5 g aluminum?
    3. Calculate the number of atoms of aluminum needed to react with 14.0 g of O2.
    4. Calculate the number of liters of oxygen, at STP, needed to react with 35.6 grams of Al.
    5. 47.5 grams of oxygen and 46.0 grams of aluminum react in a container. How many grams of aluminum oxide are formed?
    6. 50.0 grams of aluminum reacted with excess oxygen. If only 85 grams of Al2O3 were formed, what was the percent yield?


    States of Matter

  5. State the kinetic theory of gases.
  6. How is kinetic energy related to Kelvin temperature?
  7. Why does the temperature of a boiling liguid remain the same?
  8. Review the phase diagram in the book on page 256. At a temperature of -3 °C and a pressure of 150 kPa, what state is this substance in?
  9. How do liquids evaporate?
  10. Convert the following units:
    a) 250 °C to K   b) 45 mm Hg to kPa   c) 4 K to °C

    Thermochemistry

  11. A chunk of silver has a specific heat of 0.236 J/(g x °C). How much heat is given off if a 30.0 gram piece of silver is cooled from 90.0 °C to 20.0 °C?
  12. A 10.0 gram piece of metal at 85.0 °C is dropped into 100.0 mL of 15 °C water. The final temperature of the system is 24.0 °C. What is the specific heat of the metal?
  13. The reaction CaO(s) + H2O --> Ca(OH)2 has a DH value of -65.2 kJ.
    1. Is this an endothermic or exothermic reation?
    2. If 35.0 grams of CaO reacts, how much heat is produced?
  14. Calculate the heat of reaction for Cu(s)   +   1/2 O2 (G)   -->   CuO (s) from the following reactions:
    CuO (s)   +   Cu(s) --> Cu2O (s)   DH = -11.3 kJ
    2 Cu2O (s) + O2 (g) --> 4 CuO (s)   DH = -229.2 kJ
  15. How much heat is needed to boil completely away 50.0 g of water at 25.0 °C?
  16. What is a calorimeter and how is it used?
  17. Using the standard heats of formation found in Table A.6 in the appendix, calculate the heat of reaction for
    CH4 (g) + 2 O2 (g) --> CO2 (g) + 2 H2O (l)

    Gas Laws

  18. Know Boyle's Law, Charles' Law, Guy-Lussac's Law, the combined gas law, and the ideal gas law.
  19. A gas is placed in a 3.00 L container at a pressure of 525 mm Hg. What is the new volume if the gas is compressed to 950.0 mm Hg?
  20. A gas is placed in a rigid 5.00 L container at a pressure of 95 kPa and 30.0 °C. What is the new pressure if the container is heated to 150.0 °C?
  21. 22.3 grams of hydrogen gas are placed in a 50.0 L container at a temperature of 25 °C. What is the pressure in the container?
  22. A balloon is filled to its maximum stretching point outside on a hot day. It is now taken into an air-conditioned building. How does this affect it in terms of pressure, temperature, and volume?

    Periodicity

  23. What is a period? a group?
  24. Where are each of the following located on the periodic table?
    a) transition metals   b) alkali metals   c) halogens   d) noble gases   e) alkaline earth metals
  25. Know the trends on the periodic table for atomic size (increases as you go down and to the left), electronegativity, ionic size, and ionization energy.

    Ionic Bonding

  26. How is an ionic bond formed?
  27. Use electron dot formulas to show how magnesium forms a compound with chlorine.

    Covalent Bonding

  28. What is a covalent bond?
  29. Draw Lewis dot structures for the following compounds.
    a) CHCl3   b) N2   c) SO2   d) SO4-2   e) PCl3
  30. State the molecular shape for each molecule in #28 and state whether it is polar or nonpolar.
  31. Review intermolecular forces. Know which are the weakest and which are the strongest.

    Molarity

  32. What is the molarity of a solution made by dissolving 24.8 grams of calcium hydroxide in 500.0 mL of water?
  33. How many moles of solute are present in 25.00 mL of a 0.300 M solution?
  34. How would you prepare 300.0 mL of a 0.25 M solution of NaCl from solid salt?
  35. How would you prepare 250.0 mL of a 0.40 M solution of HCl from a 6 M stock solution?

    Chemical Equilibria and Kinetics

  36. Draw an energy diagram for an exothermic reaction which shows the following: activation energy, reactants, products, DHrxn, activated complex.
  37. List the four factors that affect reaction rate and state why they affect it.
  38. State the three factors that affect equilibrium and how they affect it.
  39. Find the Keq for the following reaction when at equilibrium there are 0.30 moles of each reactant present and 0.50 moles of each product. (All compounds are gases.)
    2 C2H2   +   5 O2   <-->   4 CO2   +   2 H2O
  40. Use the reaction in #38 for the following questions. It is an exothermic reaction.
    1. If more oxygen is added, which direction will the equilibrium shift?
    2. If CO2 is removed, which direction will the equilibrium shift?
    3. If pressure is increased, which direction will the equilibrium shift?
    4. If temperature is decreased, which direction will the equilibrium shift?
  41. CO (g)   +   2 H2 (g)   <-->   CH3OH (g)
    Initially 0.200 moles of CH3OH is placed in a 1.00 L container. At equilibrium, 0.040 moles of H2 is formed. Find the value of Keq for this reaction.



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