Question

Molar Mass of a Condensable vapor:
The significance of immersing the flask as far as possible into the hot water bath?
= Is to allow the volatile liqued to evaporate, current?

Answer 1

It is but if you think about it and DON'T heat the ENTIRE flask, then the liquid will evaporate as you want it to but it may condense, also, on the cooler walls of the flask near the top. If this is a density or molar mass of a volatile liquid you want the entire "bulb" to contain the vapor and none of the liquid.