if you have a complete vaccuum how hard will it be to make that vaccuumed area bigger?

A piston type vacuum pump would act to move an unbalanced force. If you have a perfect vacuum on one side and atmospheric pressure on the other side, the force required to pull the piston away from the vacuum would be the differential pressure (14.7 - 0 psid) times the area of the piston. This would require work (and power) but you would get all the work back (neglecting friction) as the piston approaches the vacuum chamber. The differential pressure on the piston would be constant (as you suggest). If there is atmospheric pressure on both sides of the piston, no work (neglecting friction) will be performed (because there is no unbalanced force).

Increasing the volume of the vacuum space will not change the force required. If there is truly nothing in the vacuum then you can't make it more nothing.

When fighting the effects of a vacuum you are in reality lifting a column of air off of the earth. Think of a tube which extends from the Earths surface into space, this tube is closed on the bottom. There is a plunger at the bottom, as you lift the plunger you are lifting all the air in the tube, the vacuum forms simply because there is nothing that can enter it. The weight of the air above the vacuum will be no different if you lift the plunger 6" or 60". The volume of the vacuum is irrelevant to the force required to lift the air above it.

ok

let me say u some things

1)complete vaccum is impossible even in theory!!!

bcoz when u attain even very low pressures the molecules of the container will go in side toring of from the container

so

in the course of time if tear of completely

ok

let us assume such a container

u would ned an infinitly large force to pull it it apart

and since infinities come in to play

ur theory is correct

da y did u asked a Chemist!!!!

now ur an idiot(I am sorry just kidding!!!:-)