Calculate the value of the equilibrium constant (Kc) for the reaction shown, if SbCl5 was found to be 5.57% decomposed at 521K when its initial concentration was 7.60M.
SbCl5 <==> SbCl3 + Cl2
Assume the chlorine gas is dissolved in the same volume of solution.
K=122
I am assuming that these are solutions, somehow, but the equation you have shown doesn't tell me what they are. At 521 K I suspect we have a gaseous reaction. The reason I'm a little puzzled is that these probably are in the gaseous state, and the problem wants you to calculate Kp first, then change to Kc. Until I get clarification, I'll assume concns but I would be willing to bet good money that they are gases initially.
Write the decomposition equation.
Write the Kc expression.
Set up an ICE chart if that will help you.
Calculate concns SbCl5, SbCl3, and Cl2.
For example, the equilibrium concn of Cl2 will be 0.0557 x 7.60 M= ??
oh sorry, all of them are in gaseous states
To calculate the value of the equilibrium constant (Kc) for the given reaction, you need to use the equation and the provided information.
The equation for the equilibrium constant (Kc) is:
Kc = [Products]^n / [Reactants]^m
Where [Products] and [Reactants] represent the equilibrium concentrations of the products and reactants, respectively, and n and m are the stoichiometric coefficients of the balanced equation.
In this case, the balanced equation for the reaction is:
SbCl5 <==> SbCl3 + Cl2
The stoichiometric coefficients for this equation are 1, 1, and 1, respectively.
Given:
Initial concentration of SbCl5 = 7.60 M
Percentage decomposed = 5.57%
Therefore, the concentration of SbCl5 at equilibrium = (100% - 5.57%) = 94.43%
Now, let's substitute the values into the equation:
Kc = ([SbCl3][Cl2]) / [SbCl5]
To proceed, you need to know the equilibrium concentrations of SbCl3 and Cl2. However, we can calculate these concentrations using the provided information, assuming negligible changes in volume during the reaction.
1. Calculate the concentration of SbCl5 at equilibrium:
[SbCl5] = (94.43% / 100) * 7.60 M = 7.17 M
2. Since the stoichiometry of the reaction is 1:1:1, the concentration of SbCl3 will be equal to the concentration of Cl2 at equilibrium. Let's represent this concentration as x M.
The equilibrium concentrations are:
[SbCl5] = 7.17 M
[SbCl3] = x M
[Cl2] = x M
3. Now, substitute these values into the equilibrium constant expression:
Kc = ([SbCl3][Cl2]) / [SbCl5] = (x * x) / 7.17
4. To solve for x, use the given information that SbCl5 is 5.57% decomposed at equilibrium. This means that 5.57% of SbCl5 decomposed into SbCl3 and Cl2. Therefore, the change in concentration of SbCl5 is equal to the concentrations of SbCl3 and Cl2 formed:
Change in concentration of SbCl5 = [SbCl5] - Initial concentration of SbCl5
Change in concentration of SbCl5 = 7.17 M - 7.60 M = -0.43 M
Since the stoichiometry of the reaction is 1:1:1, the change in concentration of SbCl5 is equal to the concentrations of SbCl3 and Cl2 formed:
Change in concentration of SbCl3 = Change in concentration of Cl2 = -0.43 M
5. Substitute the change in concentration values into the equilibrium concentrations:
[SbCl3] = x M + (-0.43) M = x - 0.43 M
[Cl2] = x M + (-0.43) M = x - 0.43 M
6. Plug these values into the equilibrium constant expression:
Kc = ((x - 0.43) * (x - 0.43)) / 7.17
Now, you can solve this equation to find the value of Kc.