Honestly it does not matter what length your chapters are. Chapters can be anything from a few words long to nearly 10,000. Some books don't have chapters at all, just scene breaks. An agent or publisher is not going to reject a novel because your chapters are not all 5,000 words long. Neither are they going to advise you on the length of chapters, that's your department as the writer. Chapters and scene breaks are a means of controlling the pitch and flow of a novel. A means of moving on the story and changing scene, and POV. You use them as you see fit to create your story.
Absolutely agree. How a book is broken up is far less important than issues such as pacing, IMO. A well paced chapter will flow quickly, regardless of its length.
Also, I always remember the book adaption of the film "Gremlins", one of the chapters was simply the line: "Billy forgot."
On a related note then, when is a first novel too long? Mine's staying stubbornly around the 150000 word mark, despite a lot of editing.
So far as I understand it, 200k words is quite acceptable in the fantasy genre especially (but also probably sf), as there's a real hunger for longer works. Think George R R Martin, Peter Hamilton, Tad Williams, etc.