Calculating Kc and Kp
Calculate Kc and Kp for the following equation:
2NOBr --> 2NO + Br2
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at 727°C, the equilibrium concentration of NO is 1.29 M, Br2 is 10.52 M, and NOBr is 0.423 M.
Kc = 97.8
Kp = 8.03 x 10^4
Consider the following reaction at 298 K:
2NO(g) + Cl2(g) ⇆ 2NOCl(g) Kp = 31.6
In a reaction mixture at equilibrium, the partial pressure of NO is 128 torr and that of Cl2 is 176 torr. Calculate the partial pressure of NOCl at equilibrium.
Hint: 1 atm = 760 torr
NOCl = 0.455 atm
Determine how the following changes will effect the concentrations of the reactants and products.
2 NO2 (g) ⇋ N2O4 (g) △H = -58 kJ
A. Addition of N2O4
B. Removal of NO2
C. Increase in volume
D. Decrease in temperature
A. NO2 increases, N2O4 decreases
B. NO2 increases, N2O4 decreases
C. NO2 increases, N2O4 decreases
D. NO2 decreases, N2O4 increases
The equilibrium constant Kc for the following reaction at 800°C is 3.74 x 10^5
H2(g) + I2(g) ⇆ 2HI(g)
If 6.25 moles of HI were initially added to a 15.0-L empty vessel, what would the concentrations of H2, I2, and HI be at equilibrium.
H2 = 6.80 x 10^-4 M
I2 = 6.80 x 10^-4 M
2HI = 0.416 M
The equilibrium constant values for the reactions below were determined at a certain temperature:
S(s) + O2(g) ⇆ SO2(g) Ka = 3.2 x 10^45
2S(s) + 3O2(g) ⇆ 2SO3(g) Kb = 3.2 x 10^124
Using these data, determine the equilibrium constant Kc for the following reaction:
2SO2(g) + O2(g) ⇆ 2SO3(g) Kc = ?
A 2.5 L reaction vessel contains 0.55 mol PCl5, 0.55 mol PCl3, and 0 mol Cl2. Find the molarity of Cl2 at equilibrium.
PCl5 ⇋ PCl3 + Cl2 , KC = 3.8 x 10−2
0.038 M Cl2
heat + 2 NO2(g) ⇋ N2O4(g)
Which of the following changes will not be effective in increasing the amount of N2O4? (more than one answer may be chosen)
a decrease in volume, an increase in heat, an addition of N2, or removal of N2O4
Addition of N2
For the reaction shown below, Kc = 0.654 at 600 K.
N2O4(g) ⇆ 2NO2(g)
If initially, 0.0600 M of N2O4 are present in the reaction vessel, what are the equilibrium concentrations of the gases at 600 K?
N2O4 = 0.0134 M
NO2 = 0.0932 M
At 300 K, the equilibrium concentrations for the following reaction are [CH3OH] = 0.240 M, [CO] = 0.350 M, and [H2] = 1.65 M for the reaction
CH3OH(g) ⇆ CO(g) + 2H2(g)
Calculate Kp at this temperature.
Kp = 2.4 x 10^3
What is the equilibrium concentration of Br2 if [HBr] = 0.35 M and [H2] = 0.22 M at equilibrium?
H2(g) + Br2(g) --> 2HBr(g) K = 62.5
8.9 x 10^-3 M Br2
Given: 2A(g) B(g) + C(g) ∆H˚= +27 kJ, K=3.2 x 10-4
Which of the following would be true if the temperature were increased from 25˚C to 100˚C?
1. The value of K would be smaller.
2. The concentration of A(g) would be increased.
3. The concentration of B(g) would increase.
Statement 3
Consider the following equilibrium:
2NO(g) + 2H2(g) ⇆ N2(g) + 2H2O(g)
Initially, there are 0.15 moles of NO and 0.25 moles of H2, in a 10.0-L container. If there are 0.056 moles of NO at equilibrium, how many moles of N2 are present at equilibrium?
0.047 mol N2
The equilibrium constant for the formation of calcium carbonate from the ions in solution is 2.2 × 10^8 according to the reaction:
Ca(aq) + CO3 (aq) CaCO3(s) K = 2.2 × 10^8
What is the value of the equilibrium constant for the reverse of this reaction?
CaCO3(s) Ca (aq) + CO3 (aq) K = ?????
K = 4.5 × 10–9
What is the equilibrium concentration of C?
A(g) + B(g) --> 2C(g) + D(g) K = 6.0 x 10-7
A = 4.5 × 10–4
B = 0.25
C = ?
D = 1.4 × 10–3
2.16 x 10-4 M
Given the following reaction at equilibrium, which of the following alterations will increase the amount (in moles) of SO2Cl2: (there is only one correct answer)
SO2(g) + Cl2(g) SO2Cl2(g) ∆H˚ = -67 kJ
a. adding heat to the system
b. adding Cl2 to the system.
c. removing Cl2 from the system.
d. increasing the volume of the reaction vessel.
B
Consider the following reaction characterized with Kp = 2.34 x 10-4 at 250 K:
I2(g) + Cl2(g) ⇆ 2ICl(g)
A reaction mixture initially contains I2 with partial pressure of 655 torr and Cl2 with partial pressure of 864 torr at 250 K. Calculate the equilibrium partial pressure of ICl.
11.5 torr