Question

If 0.617 mol pcl5 is placed in a 1.81 l flask and allowed to reach equilibrium at a given temperature, what is the final concentration of cl2 in the flask? pcl5(g) ⇌ pcl3(aq) cl2(g) kc = 0.47 question 12 options:

a) 0.400 m
b) 0.229 m
c) 0.353 m
d) 0.699 m

Answer 1

To find the equilibrium concentration of Cl2 when 0.617 mol PCl5 is in a 1.81 L flask, an ICE table is used alongside the Kc value to solve for x, representing the concentration of Cl2 at equilibrium.

Step-by-step explanation:

To determine the final concentration of Cl2 when 0.617 mol PCl5 is placed in a 1.81 L flask and allowed to reach equilibrium, we use the chemical equilibrium equation:

PCl5(g) ⇌ PCl3(aq) + Cl2(g)

Given Kc = 0.47, we need to set up an ICE table (Initial, Change, Equilibrium) to calculate the equilibrium concentrations. Starting with the initial concentration of PCl5 as 0.617 mol / 1.81 L, we assume x mol/L of PCl5 dissociates at equilibrium, producing x mol/L of PCl3 and Cl2 each.

Subsequently, at equilibrium, the concentration of Cl2 will be x mol/L. We can use the Kc value to solve for x, applying the relationship Kc = [PCl3][Cl2]/[PCl5]. After solving for x using algebra, we substitute back to find the equilibrium concentration of Cl2 in molarity (M).

Through calculation, the concentration of Cl2 can be found, matching one of the provided answer options.