What is the lifting power of helium?

Question

Assuming a weightless container, what volume of helium would be required to lift a one-pound (or one-kilogram) weight?

Answer 1

http://www.newton.dep.anl.gov/askasci/phy99/phy99471.htm

Answer 2

Fluid objects tend to move from a place of higher concentration to a place of lower concentration. (or pressure)
What you're observing is not 'helium lifting' anything, but heavier molecules moving towards the center of gravity (the earth) and displacing the helium as they move. Thus, the helium rises.

The greater the difference in concentration, the more energy. So, in short, it depends on what the atmospheric pressure is, and how far your 1kg object has to travel.

Answer 3

First of all the question is to lift were? You did not specify the medium. I assume it is air, and then I would like to know what is the air temperature and pressure. We could split hair on influence of humidity, but let us keep it simple.
Let us make some use of the buoyancy law our friend Archimedes introduced some 2200 years ago. I general we have

V (He) + m < V (Air) then
V>m/(Air – He) If the density of air and helium are expressed in Kg-Meter then
V>1 / (Air – He)
Where
V - minimum volume of helium required
Air - Density of air (or the density of the medium)
He – Density of helium.
m – is mass to be lifted.

For density of air please see ref (1)
For density of helium and air please see ref (2)

Have fun

Answer 4

Air density 1.29 kg/m3
Helium density 0.16 kg/m3

Different = 1.13 kg/m3 = lift per m3 of the balloon

Therefore 1 kg of lift requires a balloon 1/1.13 m3 in size