Phosphorus pentachloride, PC(l)5, decomposes when heated at 160 degrees C follow
ID: 1021678 • Letter: P
Question
Phosphorus pentachloride, PC(l)5, decomposes when heated at 160 degrees C following the equilibrium reaction below, with an equilibrium constant K equals to 0.0211.
PCl5 (g) -------> <-------- PCl3 (g) + Cl2 (g)
a. If the inital concentration of PCl5, is 1.00 mol/L, what is the equilibrium composition of PCl5, if the partial pressure of PCl5, at equilibrium is P=30.76atm. (Note: all the gases in this experiment follow the ideal gas law, PxV=nxRxT, where R=0.0821 Lxatm/Kxmol and T in Kevlin)
b. Calculate the equilibrium composition of the other gaseous species in the mixture (use a table to summarize your calculations).
Explanation / Answer
PCl5 --------> PCl3 + Cl2
PV = nRT
n/V = P/RT
T = 160C0 = 160+273 = 433K
n/V = 30.76/0.0821*433
= 0.865mole/L
PCl5 --------> PCl3 + Cl2
i 1 0 0
C -0.135 0.135 0.135
E 0.865 0.135 0.135
Kc = [PCl3][Cl2]/[PCl5]
= 0.135*0.135/0.865 = 0.0211 >>>> answer