flight time from montreal to frankfurt germany

A direct flight Montreal - Frankfurt ( Lufthansa) lasts approximately 7hrs 20min.
This is only the flight's duration without check-in, luggage claim, customs, etc
Nonstop travel time with Air Canada ( departing from YUL ) is 7:15hrs.
Flights with one change of plane need 9 hrs and more.That all depends whether the flight you'd be taking has stopover(s) or is a direct one.