Metal carbonyls, which have the general formula M(CO)x (x can be various possible subscripts depending on the particular metal used), are important intermediates in the purification and reactivity of transition metals. Consider the following synthesis of an unknown metal carbonyl, with the indicated equilibrium constant. M (s) + x CO (g) --> M(CO)x (g) Kp = 0.133 If you add an unknown amount of the metal and carbon monoxide gas to an empty reaction flask, and at equilibrium the pressure of carbon monoxide is 2.28 atm and metal carbonyl is 7.80 atm, what was the initial pressure of carbon monoxide that you added?