Answer:
The concentration of the reaction PCl5 is 1, 133M
Step-by-step explanation:
The equilibrium constant Kc is the ratio of the products to their reactants, each elevated with its stoichiometric coefficients. In this case:
Kc= (products)/(reactants)
Kc= (PCl3) x (Cl2) / (PCl5)
(PCl5)= (PCl3) x (Cl2)/ Kc = 0,170M x 0280 M/ 0,0420
(PCl5)= 1, 133 M