Phosphorus pentachloride dissociates as follows, in a closed reaction vessel
PCl₅ (g) PCl₃ (g) + Cl₂ (g)
If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of PCl₅ is x, the
partial pressure of PCl₃ will be
JEE Main 2006 · Annual, Paper 1 · Q397