Given the equilibrium system PCL5(g) <----->PCl3(g) + Cl2(g)
K = 12.5 at 60 degrees celsius. A 1.0 L reaction vessel is analyzed and found to contain 3.2 mol Cl2(g), 1.5 mol PCl3(g) and 2.0 mol PCl5(g). Show that the reaction mixture has not yet reached equilibrium.
Set up the expression for Keq.
Then calculate the reaction quotient and compare with Keq. Post your work if you get stuck.
To determine if the reaction mixture has reached equilibrium, we need to calculate the reaction quotient (Q). The reaction quotient is calculated using the concentrations (or partial pressures) of the reactants and products at a particular point in time.
The reaction quotient (Q) is calculated using the formula:
Q = [PCl3] * [Cl2] / [PCl5]
Given that we have 3.2 mol Cl2(g), 1.5 mol PCl3(g), and 2.0 mol PCl5(g) in a 1.0 L reaction vessel, we can calculate the concentrations as follows:
[Cl2] = 3.2 mol / 1.0 L = 3.2 M
[PCl3] = 1.5 mol / 1.0 L = 1.5 M
[PCl5] = 2.0 mol / 1.0 L = 2.0 M
Substituting these values into the reaction quotient formula, we get:
Q = (1.5 M) * (3.2 M) / (2.0 M) = 2.4 M^2
Comparing the value of Q (2.4 M^2) with the equilibrium constant K (12.5), we can see that Q < K. This means that the reaction mixture is not yet at equilibrium. In an equilibrium situation, Q should be equal to K.
Since Q < K, it indicates that there is an excess of reactants, and the forward reaction has not progressed enough to reach equilibrium. Therefore, the reaction mixture has not yet reached equilibrium.