1) At 773 C, an equilibrium mixture of the following system was analyzed:
The concentrations of each component were found to be: [CO] = 0.105M, [H2] = 0.250M, and [CH3OH] = 0.00261M. Calculate the value of Kc for this system.
2) At 460 C, the reaction: SO2(g) + NO2(g) <--> NO(g) + SO3(g) has a Kc = 85.0.
A reaction flask contains each gas at the following concentrations:
[SO2] = 0.0100M [NO2] = 0.0400M [NO] = 0.00150M [SO3] = 0.00300M
a) Is the system in a state of equilibrium?
b) If not, which direction must the reaction proceed to get to equilibrium?
3) At a certain temperature Kc = 0.20 for the following equilibrium:
A reaction vessel contained these gases at the following concentrations:
[PCl3] = 0.500M [Cl2] = 0.200M [PCl5] = 0.500M
a) Is the system in a state of equilibrium?
b) If not, which direction must the reaction proceed to get to equilibrium?
c) Determine the final equilibrium concentrations of each component.
4) At 25 C the Kp = 14.2 for the following equilibrium system: N2O4(g) <--> 2NO2(g)
a) In a reaction vessel at equilibrium the pN2O4 = 30.4kPa, what is the pNO2?
b) What is the total pressure of this gas mixture?
5) Ethanol can be produced from ethene in the following equilibrium system:
At a certain temperature, Kc = 300.3 for this system. If 1.00 mole of ethene is mixed with 1.00 mole of water vapour in a 2.00L flask and allowed to react.
a) Determine the number of moles of ethanol that would be produced at equilibrium.
b) What is the percentage yield of this reaction?
c) In order to push this reaction to a yield of 98.0%, it was decided to increase the original concentration of ethene. How many moles of ethene must be added to the original mixture to achieve this goal?
6) At a high temperature, 0.500 mol of HBr was placed in a 1.00L flask and allowed to decompose according to the reaction: 2HBr(g) H2(g) + Br2(g). At equilibrium, the concentration of Br2 was measured to be 0.130M. Determine the Kc for this reaction at this temperature.
7) The reaction N2(g) + 3H2(g) <--> 2NH3(g) has a Kc = 64 at a given temperature. If an equilibrium mixture of these gases contains 0.280M NH3 and 0.00840M N2 what is the concentration of H2(g)?
8) At a given temperature, the equilibrium constant, Kc = 0.500 for the following system: SO3(g) + NO(g) <--> NO2(g) + SO2(g)
If 0.100 mol of SO3 and 0.200 mol of NO are added to a 2.00L flask and allowed to react, determine the equilibrium concentrations of each gas.
9) For the reaction: 2NO2(g) <--> N2O4(g) Kc = 1.5 at a certain temperature. An equilibrium mixture of these gases is found to contain 0.48 mol of N2O4 and 0.80 mol of NO2 in a 2.0L flask.
a) According to LeChatelier's Principle, what reaction should be favoured if the volume of this flask is compressed to 1.5L?
b) Show how the equilibrium constant can be used to confirm the answer predicted by LeChatelier.
10) The reaction 2HCl(g) <--> H2(g) + Cl2(g) has Kc = 3.2x10-34 at 25 C. If a reaction vessel initially contains 2.00M of HCl and is allowed to come to equilibrium, what will be the final concentrations of H2 and Cl2?
11) If 0.100 mol of H2 and 0.100 mol of Br2 are added to a 10.0L flask and allowed to react at 25 C in the following reaction:
a) Determine equilibrium concentrations of all gases at equilibrium.
b) What is the percentage yield of this reaction?
12a) Assuming the density of water of 1.0g/mL, calculate the molar concentration of pure water in: i) 18.0mL of H2O, ii) c) 1.0L of H2O
12b) The density of silver chloride (AgCl) is 5.56g/cm3. Determine the molar concentration of AgCl in a pure solid sample.
12c) Why can we omit the concentrations of pure liquids and pure solids from the equilibrium constant expression for heterogeneous equilibria?
13) The heterogeneous reaction: 2HCl(g) + I2(s) 2HI(g) + Cl2(g) has a Kc = 1.6x10-34 at 25 C. If 1.00 mol of HCl(g) is allowed to react with I2 in a 1.00L flask at 25 C, determine the equilibrium concentrations of HI and Cl2 in the container?
14) At 125 C the Kc = 2.4x10-4 for the decomposition of sodium hydrogen carbonate: 2NaHCO3(s) Na2CO3(s) + CO2(g) + H2O(g)
a) What is the equilibrium concentration of CO2 in this system if the concentration of H2O(g) is found to be 2.50x10-1M
b) If at the same temperature Kp = 2.6x103. If the equilibrium pCO2 was found to be 70.5kPa, what is the pH2O in this system? What is the total gas pressure?
c) When NaHCO3 is allowed to decompose at 125 C, the resulting concentrations of H2O and CO2 are both 1.55x10-2M. If this equilibrium system is stressed by the addition of an extra 0.200M of CO2, determine the new equilibrium concentrations of each gas.