Class 11 Chemistry Gases & Solutions States of Matter
Payload is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the payload, when a balloon of radius 10 m of mass 100 kg is filled with helium at 1.66 bar at 27 . (Density of air = 1.2 kg m and R = 0.083 bar dm K mol)
Solution: The volume of the balloon is .
The radius of balloon is 10 m.
Hence, the volume of the balloon is .
The mass of displaced air is obtained from the product of volume and density. It is .

The number of moles of gas present are .

Note: Here, the unit of volume is changed from to
.

Mass of helium present is obtained by multiplying the number of moles with molar mass. It is kg.
The mass of filled balloon is the sum of the mass of the empty ballon and the mass of He. It is  kg.
Pay load mass of displaced air mass of balloon kg

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