At a certain temperature, 0.700 mol of SO3 is placed in a 3.50-L container.
At equilibrium, 0.100 mol of O2 is present. Calculate Kc.
2SO3=2SO2 +)2
(SO3) = 0.700/3.50 = 0.2 mol
.........2SO3 ==> 2SO2 + O2
I........0.200.....0......0
C........-2x......2x......x
E......0.200-2x....2x.....x
At equil, x = 0.1 mol.
Calculate the concns of each and substitute into the Kc expression; calculate Kc.
how do i find the concentrations?
The problem tells you that at equilibrium the amount of O2 = 0.1 mol.
That is in 3.50L; therefore, (O2) = 0.1mol/3.50L = x = 0.0286M
Then (SO3) = 0.200-2x
(SO2) = 2x
(O2) = x = 0.0286
Where do you substitute Kc into the expression?
To calculate the equilibrium constant Kc, you need to write the balanced chemical equation for the reaction and use the concentrations of the reactants and products at equilibrium.
The balanced chemical equation for the reaction is:
2SO3 ⇌ 2SO2 + O2
At equilibrium, you are given that 0.700 mol of SO3 is placed in a 3.50-L container and 0.100 mol of O2 is present.
Now, you need to calculate the concentrations (in mol/L) of each species at equilibrium.
For SO3:
Concentration of SO3 = moles/volume of the container
Concentration of SO3 = 0.700 mol / 3.50 L = 0.200 M
For SO2:
Since 2 moles of SO2 are formed for every 2 moles of SO3, the concentration remains the same as SO3.
Concentration of SO2 = 0.200 M
For O2:
Concentration of O2 = moles/volume of the container
Concentration of O2 = 0.100 mol / 3.50 L = 0.0286 M (rounded to 4 decimal places)
Now that you have the concentrations of each species at equilibrium, you can calculate the equilibrium constant, Kc, using the equation:
Kc = [SO2]^2 * [O2] / [SO3]^2
Substituting the concentrations we calculated:
Kc = (0.200)^2 * 0.0286 / (0.200)^2
Simplifying, we get:
Kc = 0.0286
Therefore, the equilibrium constant Kc for the given reaction is 0.0286.