Almost certainly its not unusual at all.

Furthermore with the identifying numbers it should be possible to look up the make and model of aircraft.

And while that won't prove chemtrails in this instance, it's certainly capable of disproving them. Like if that plane is a tiny little Cessna then we know it's not carrying enough chemicals to be dumping over such a large area.

The level of research put into this post is so low it's not even worth the time you and I have spent commenting on it.