At 80.°C, Kc = 1.87 10-3 for the reaction.

Question

At 80.°C, Kc = 1.87  10-3 for the reaction.
PH3BCl3(s)  PH3(g) + BCl3(g)
(a) Calculate the equilibrium concentrations of PH3 and BCl3 if a solid sample of PH3BCl3 is placed in a closed vessel at 80.°C and decomposes until equilibrium is reached.
(b) If the flask has a volume of 0.450 L, what is the minimum mass of PH3BCl3(s) that must be added to the flask in order to achieve equilibrium?

bobpursley · Accepted Answer

Kc=[PH3][BCl3] since those are both equal concentratons, then x^2=Kc x= sqrt Kc b. mass of PH3+massBCl3=2xVolume=2*.450*sqrtKc

Stan3000 · Answer

thnx :)

Anonymous · Answer

why do both PH3 and BCL3 have equal concentrations at equilibrium?

Anonymous · Answer

Same leading digit, one mole each