Consider the following reaction:
POCl
3(g)

POCl(g) + Cl
2(g) with
Kc = 0.450
A sample of pure POCl
3(g) was placed in a reaction vessel and allowed to decompose according to the above reaction. At equilibrium, the concentrations of POCl(g) and Cl
2(g) were each 0.150 M. What was the initial concentration of POCl
3(g)?
◦ 0.225 M
◦ 0.200 M
◦ 0.633 M
◦ 0.483 M
◦ 0.350 M