1. Consider the dissociation of PCl5

PCl5 → PCl3 + Cl2

1. Give the geometry of PCl5 and PCl3.
2. Use the following bond energies to calculate Ã†HÂ° for this reaction in the gas phase:

P-Cl 326 kJ/mol; Cl-Cl 240 kJ/mol

3. Calculate the ΔH° for the reaction using the following standard heats of formation (in the gas phase):

PCl5 -371 kJ/mol; PCl3 -279 kJ/mol

4. When 1.0 mole of PCl5 is dissolved in 2.0 L of solution at some temperature and the reaction is allowed to reach equilibrium, 0.60 mole of PCl3 is obtained. Calculate the equilibrium constant.
5. If the reaction is started again with 2.0 mole of PCl5 dissolved in 2.0 L of solution, how much PCl3 will be obtained when equilibrium is established?
2. When the reaction

2CO + O2 → 2 CO2

is started with a 1.0 M solution of CO2, 0.60 M CO will be present at equilibrium.

1. Calculate the equilibrium constant.
2. How much CO2 must be added to 1.0 L of this solution in order to obtain 1.0 mole of CO at equilibrium?
3. How much O2 must be removed from 1.0 L of the original solution in order to lower the concentration of CO2 to 0.20 M?
3. Consider the reaction of SiO2 with carbon.
1. Write an equation for the reaction. Include the states of all species at room temperature.
2. Give the structure of SiO2.
3. When the reaction is carried out in a 1.0 L flask and 40 g of SiO2 are heated to some temperature with 12 g carbon, 0.10 mole of CO2 is obtained at equilibrium. Calculate the equilibrium constant.
4. If 0.10 mole of CO2 were added to this equilibrium mixture what would the equilibrium amount of carbon and CO2 be?

• Introduction
• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7
• Chapter 8
• Chapter 9
• Chapter 10
• Chapter 11
• Chapter 12
• Chapter 13
• Chapter 14
• Chapter 15
• Chapter 16
• Chapter 17
• Chapter 18