Solve 3 Chemical Equilibrium Questions & Calculate Kc

[Maximillien]

Hi, I have 3 questions i can't seem to solve anyways thanks in advance.

1) If the equilbrium constant at a cetain temperature is 24 for the reaction, 2NO(g) <-> N2(g) + 02(g). Both of the systems listed below cannon be in equilbrium because at this temperature because there is only one value of Kc.

[NO] = System 1 - System 2
1.06 1.56
[N2]
[O2]

Since the equilbrium constant does not have units it doesn't matter which unit we use for concentration when calculating Kc.

2a) At T1, K=0.013
At T2, K = 083

If 1.00 mole of A is placed in a 1.00L reaction vessel, at which temperature will the amount of B at equilbfrium be higher? Explain your answer.

2b) If delta H < 0, which temperature is higher? T1 or T2? Explain your answer.

3) Use the information below to calculate Kc for the follwing reactiosn at 600 decrees celcius

C02(g) + H2(g) <-> CO(g) + H2O(g)

A gas mixture that consits of equal amounts of Co and H20 was injected into a 1.97 rigid walled container at 600 degreees ceclius until the pressure reached 7.25 atm. When the reaction reaced equilbirum, 0.024 mole Of CO were present.

Thx much.

 

[Snazzy]

So...what have you tried so far?

 

[Blueshift5]

1) To calculate Kc, we need to set up the equilibrium expression and plug in the given values for the concentrations of the reactants and products. In this case, the equilibrium expression is Kc = [N2][O2]/[NO]^2. Plugging in the concentrations from System 1, we get Kc = (1.06 x 1.06)/(1.56)^2 = 0.46. Similarly, for System 2, we get Kc = (1.56 x 1.56)/(1.06)^2 = 2.32. Since these two values of Kc are not equal, neither system is at equilibrium.

2a) To determine which temperature will result in a higher amount of B at equilibrium, we need to compare the values of Kc at T1 and T2. Since Kc is directly proportional to temperature, a higher value of Kc indicates a higher amount of B at equilibrium. Therefore, at T2, the amount of B at equilibrium will be higher.

2b) If delta H is negative, it means that the reaction is exothermic. In this case, at T2, the temperature is higher and therefore the reaction will favor the products, resulting in a higher amount of B at equilibrium.

3) To calculate Kc, we need to use the ideal gas law to convert the given pressure and number of moles into concentrations. The ideal gas law is PV = nRT, where P is pressure, V is volume, n is number of moles, R is the gas constant, and T is temperature. Rearranging this equation, we get n/V = P/RT. Plugging in the given values, we get n/V = 7.25/0.0821 x 873 = 0.0951. Since the gas mixture consists of equal amounts of CO and H2O, the concentration of CO is 0.0951/2 = 0.04755 and the concentration of H2O is also 0.04755. Plugging these values into the equilibrium expression Kc = [CO][H2O]/[CO2]

, we get Kc = (0.04755)^2/(0.04755)^2 = 1. Therefore, at 600 degrees Celsius, Kc for this reaction is 1.