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Equilibrium Constant
- Consider the following reaction
2 SO 2 (g) + O 2 (g) 2 SO 3 (g)
Write the equilibrium expression, Kc.
- Consider the following reaction
CaCO 3 (s) CaO (s) + O 2 (g)
Write the equilibrium expression, Kc.
- Consider the following reaction
2 SO 2 (g) + O 2 (g) 2 SO 3 (g)
Write the equilibrium expression, Kp.
- Consider the following reaction
H 2 O (g) + C (s) H 2 (g) + CO (g)
Write the equilibrium expression, Kp.
- Consider the decomposition of nitrous oxide, laughing gas,
2N 2 O (g) 2 N 2 (g) + O 2 (g)
At 25o^ C, Kc is 7.3 x 10 34.
(a) Based on the information given, what can you say about the rate of decomposition of the reaction? (b) Based on the information given, does nitrous oxide have a tendency to decompose into nitrogen and oxygen? (c) What is the value of Kp for the reaction at 25 o^ C?
- Consider the following reaction
CO 2 (g) + H 2 (g) CO (g) + H 2 O (g)
Calculate the value of the equilibrium constant, Kc , for the above system, if 0.1908 moles of CO 2 , 0.0908 moles of H 2 , 0.0092 moles of CO, and 0.0092 moles of H 2 O vapour were present in a 2.00 L reaction vessel at equilibrium.
- Consider the following reaction
C 2 H 4 (g) + H 2 (g) C 2 H 6 (g) K (^) c = 0.
What is the concentration for each substance at equilibrium if the initial concentration of ethene, C 2 H 4 (g) , is 0.335 M and that of hydrogen is 0.526 M?
- Consider the following reaction
2 NO (g) + 2 H 2 (g) N 2 (g) + 2 H 2 O (g)
Determine the value of the equilibrium constant, Kc, for the reaction. Initially, a mixture of 0.100 M NO, 0.050 M H 2 , 0.100 M H 2 O was allowed to reach equilibrium (initially there was no N 2 ). At equilibrium the concentration of NO was found to be 0.062 M.
- Consider the following reaction
N 2 O 4 (g) 2 NO 2 (g)
A reaction flask is charged with 3.00 atm of dinitrogen tetroxide gas and 2.00 atm of nitrogen dioxide gas. At 25 o^ C, the gases are allowed to reach equilibrium. The pressure of the nitrogen dioxide was found to have decreased by 0.952 atm. Estimate the value of Kp for this system.
- Consider the following reaction. The initial concentrations are [HSO 4 โ^ ] = 0.50 M, [H 3 O+] = 0.020 M, [SO 4 2โ^ ] = 0.060 M.
HSO 4 โ^ (aq) + H 2 O (l) H 3 O+^ (aq) + SO 4 2โ^ (aq) K = 0.
(a) Which way would the reaction shift to reach equilibrium? (b) What are the equilibrium concentrations of the products and reactants.
NO H 2 N 2 H 2 O
[I] 0.100 0.0500 0 0.
[C] -2x -2x +x +2x [E] 0. From ICE table 2x = 0.
Therefore, substitute for x and calculate [E] for each species:
NO H 2 N 2 H 2 O [I] 0.100 0.0500 0 0. [C] - 0.038 - 0.038 +0.019 +0. [E] 0.062 0.012 0.019 0.
K = 22
2
( 0. 062 )( 0. 012 )
= 6.5 x 10^2
N 2 O 4 NO 2
[I] 3.00 2.
[C] +x -2x = - 0. [E] From ICE table x = 0.952/
Therefore, substitute for x and calculate [E] for each species:
N 2 O 4 NO 2 [I] 3.00 2. [C] +0.476 -0. [E] 3.476 1.
K =
( 1. 048 )^2
- (a) Use the trial Keq , Q, to determine the reaction direction.
Q =
Q < Keq , therefore, equilibrium will shift to the right to produce more products.
(b)
K =
(0.050-x)
(0.020 +x)(0.060+x)
To solve, need to use the quadratic equation
x = 0.0372 or โ0.129 *
For x = 0.0372, [HSO 4 โ^ ] = 0.46 M; [H 3 O+] = 0.057 M; [SO 4 2โ^ ] = 0.097 M
- For x = -0.129, [HSO 4 โ^ ] = 0.63 M; [H 3 O+] = -0.109 M; [SO 4 2โ^ ] = -0.069 M it yields negative concentrations.
Therefore, the correct equilibrium concentrations are: [HSO 4 โ^ ] = 0.46 M; [H 3 O+] = 0.057 M; [SO 4 2โ^ ] = 0.097 M
HSO 4 โ^ H 3 O+^ SO 4 2โ
[I] 0.50 0.020 0.
[C] -x +x +x [E] 0.50 -x 0.020+x 0.060+x
