Question

A balloon filled with helium rises to a certain height at which it gets fully inflated to a volume of `10^(5)` litres. If at this altitude, temperature and atmospheric pressure are 268 K and `2xx10^(-3)` atm respectively, what weight of helium will be required to fully inflate the balloon ?

Answer 1

For the fully inflated balloon, we have
`V=10^(5)" L", T=288" K", P=2xx10^(-3)" atm"`
The aim is to find the mass of helium present in the balloon under these conditions.
`PV=nRT=(w)/(M)RT`
or `" " w=(MPV)/(RT)=(4 g mol^(-1)xx(2xx10^(-3)" atm")(10^(5)"L"))/((0.0821" L "atm K^(-1)mol^(-1))(268 K))=36.36 g`