The equilibrium composition for the reaction is -
PCl3+Cl2⇌PCl5
0.20 0.10 0.40 mole/litre
If 0.20 mole of Cl2 is added at same temp. Find equilibrium concentration of PCl5 KC=20
0.48 moles
PCl3+Cl2⇌PCl5
0.20 0.10 0.40 moles/litre
If 0.20 mole of Cl2 is added then at equilibrium
0.20 - x 0.30 - x 0.40 + x
Kc[PCl5][PCl3][Cl2]20=(0.40+x)(0.20−x)(0.30−x)x=0.08 [PCl5]=0.4+0.08=0.48 moles