How heavy should a Chinese chef's knife be?
A chinese style chef's knife, also known as the cai dow, or vegetable cleaver(trial subscription required, but an excellent article), is superficially similar to a western cleaver. The cleaver is typically a very robust blade, thick and weighty, meant for separating meat at the joint, splitting ribs and chops, and other tasks that require a lot of weight and a stiff blade.

The chinese chef's knife will be much thinner and lighter, comparable to a western chef's knife or Japanese nakiri. The broad face is for scooping up ingredients from the cutting board and controllability rather than mass and strength. From a brief blog entry from Kitchn on the knife -


  In her book Shark’s Fin and Sichuan Pepper: A Sweet-Sour Memoir of
  Eating in China, Fuchsia Dunlop explains, “The Chinese cleaver is not
  a butcher’s knife...The everyday cleaver, the cai dao or vegetable
  knife, is unexpectedly light and dexterous, as suitable for slicing a
  small shallot as a great hunk of meat, and used by everyone from the
  most macho chef to the frailest old lady.”