The gas phosphine, PH₃, decomposes by the reaction 2 PH₃(g) → 2 P(s) + 3 H₂(g). In an experiment, pure phosphine was placed in a rigid, sealed flask of volume 1.00 L at 0.64 bar and 298 K. After equilibrium was attained, the total pressure in the flask was found to be 0.93 bar. 

(a) Calculate the equilibrium partial pressures of H₂ and PH₃. 

(b) Calculate the mass (in grams) of P produced once equilibrium was reached. 

(c) Calculate K for this reaction.