Question

Phosphorus pentachloride reacts to form phosphorus trichloride and chlorine gas when heated. A 2.00 liter vessel contains 0.020 moles of phosphorus trichloride and chlorine at equilibrium. How many moles of phosphorus pentachloride are present? Kc=0.0415

Answer 1

Here is step by step for nearly all these prolbems. Go thru the rest, and we can critique for you.

a. Write the balancee equation:
PCl5 <<>> PCl3 + Cl2
b. Write the equilibrium expression:

k= [PCl5][Cl2]/[PCl5]
because moles/volume=concentration, and volume is 2 liters, then
0.0415=.01*.01/x
solve for x, the concentration of PCl5
moles present? x*volume for moles=2*x