A spherical ballon of 21 cm diameter is to be filled with `H_(2)` at NTP from a cylinder containing the gas at 20 atm at `27^(@)C` .If the cylinder can hold 2.80 L of water , calculate the number of ballons that can be filled up .

Explanation

The capacity of cylinder = 2.80 L
Let n moles of hydrogen contained in cylinder and `n_(0)=` moles of hydrogen required to fillone balloon.
` n = ( PV)/( RT ) = ( 20 xx 280)/( 0.0821 xx 300) = 2.273`
`n_(0) =( "volume of balloon ")/( 22400)`
(Note `:` the balloons are being filled at S.T.P. )
`=( 4//3pi r^(2))/( 22400) = ( 4//3 xx 3.14 xx ( 10.5)^(3))/( 22400) = 0.2164`
`rArr` Number of balloons that can be filled `=( n )/( n_(0)) = 10.50 ~~10`