CK 225 then UA 5940 at O'Hare
Seattle (SEA) → Chicago → Tucson
Timetable, Chicago time
07:42CK 225 from Seattle (SEA) at the gate
19:54UA 5940 to Tucson leaves the gate
12 h 12 apart on the timetable
UA 5940 leaves 12 h 12 after CK 225 arrives on the timetable: more than half a day, so not a connection we count.