Sometimes a chapter needs to be that long. There might not be a good place to break off, or you want to finish that dramatic scene in one shot without a cliffie.
There's no hard and fast rule. James Patterson writes short chapters and his books are formulaic and forgettable, aside from the distasteful fact that he review whores in public. George RR Martin writes long chapters and I can't put his books down. If an author can hold my attention for 10,000 words straight, that's brilliant.