Flight O'Hare International Airport departs from Chicago O'Hare International Airport at 15:40 and arrives at Zurich Zürich Airport at 07:45.
The flighttime is about 9h 05m. The distance travelled ("as the bird flies"): 10726 Km. So the average speed is roughly 1181 Km.
There is an 7 hour time difference between Chicago and Zurich