Chapter 14 Lecture Problems
Introduction to Equlibrium
M&M's Spreadsheet
Heterogenous Equlibrium
- For the reaction CaCO3(s) (limestone) <-> CaO(s) (lime) + CO2(g)
- At 1173 K, Kp = 1.04 atm
- Start with 250 g of CaCO3(s) and a 20 liter container
- Start with 250 g of CaCO3(s) and a 400 liter container
- Solutions
Ammonia Equlibrium
For the reaction N2 (g) + 3 H2 (g) <--> 2 NH3 (g)
- Calculate Kc
- N2 = 0.921 M
- H2 = 0.763 M
- NH3 = 0.157 M
- Calculate Q if:
N2 | H2 | NH3 |
1.831 | 0.763 | 0.157 |
10.321 | 0.763 | 0.157 |
0.921 | 0.0363 | 0.157 |
0.0259 | 0.0277 | 0.0102 |
- Solutions
Kp and Kc
- Determining Kp, given Kc = 0.06025 liter2 mole-2 for the reaction
N2(g) + 3 H2(g) <-> 2 NH3(g)
- Solve for the equlibrium pressure of NH3, given equlibrium conditions at 25 °C where PN2 = 12 atm and PH2 = 35 atm for the reaction:
N2(g) + 3 H2(g) <-> 2 NH3(g)
- Solutions
PCl3
- Given INITIAL NON-EQULIBRIUM conditions, calculate the final EQULIBIRUM conditions. In solving this type of reaction the quadratic equation is often required. The example below shows one way to work this type of problem. For the following BALANCED reaction:
PCl3 (g) + Cl2 (g) <-> PCl5 (g)
At 230 C, Kc = 49 liter mole-1
- Initial conditions
- mass PCl3 = 50 gm
mass Cl2 = 50 gm
mass PCl5 = 0 gm
volume = 5 liter
- Solutions
NO Equlibrium
Calculate the equlibrium pressure of NO at 300, 600, and 1500 K. For the reaction:
N2 + O2 <-> 2 NO
- Given starting pressures (typical atmospheric concentrations) of:
- PN2 = 0.80 atm
- PO2 = 0.20 atm
- P NO = 0.00 atm
- And equlibrium constants
- K = 10-30.5 at 300 K
- K = 10-14.6 at 600 K
- K = 10-5.1 at 1500 K
- solutions
HOCl Equlibrium
For the system: H2O (g) + Cl2O (g) <-> 2 HOCl (g)
- Given the equlibrium partial pressures solve for Kp
- PH2O = 200.0 torr
- PCl2O = 48.7 torr
- PHOCl = 29.6 torr
- Given equlibrium partial pressures of reactants, find product
- PH2O = 23.4 torr
- PCl2O = 123.5 torr
- Given initial (non-equlibrium) pressures, find equlibrium conditions
- PH2O = 100.0 torr
- PCl2O = 50.0 torr
- PHOCl = 0.0 torr
- Solutions
Acid Base Equlibrium
- At equlibrium
- [NH3] = 0.897 M
- [NH4+ = 0.345 M
- Equlibrium Constants
- Ka = 5.6 x 10-10
- Kw = 1.0 x 10-14
- Kb = ?
- Find the equlibrium concentrations of:
- H3O+
- OH-
- Solutions
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Last Updated Friday, May 25, 2001 2:10:36 PM