A 1.604 g sample of SO3 is sealed into a 1.00 L flask, which was fist evacuated so that it contains no air or other gases.
(a) At higher temeratures, sulfur trioxide begins to decompose to give sulfur dioxide and oxygen, according to the following equilibrim.
2SO3(l) <-> 2SO2(g) + O2(g)
Write an expression for the equilibrium constant in terms of the concentrations of the gases.

(b) The flask from part (a) is heated to 900 K, and when the system has comt to equilibrium, the total pressure in the flask reaches 1.814. Find the value of the equilbrium constant for the above reaction at 900 K. (HINT: Start by finding the total number of moles of gas present at equilibrium.)