A spherical balloon of 21 cm diameter is to be filled up with hydrogen at N.T.P. from a cylinder containing the gas at 20 atmospheres at 27 ºC. If the cylinder can hold 2.82 liters of water, calculate the number of balloons that can be filled up.

No. of balloons that can be filled=V of H2 available V of one balloon Calculation of total volume of hydrogen in the cylinder at N.T.P.P1 V1 T1=P2 V2 T2P1 = 1 atm                      P2 = 20 atm  V1 = ?                              V2 = 2.82 l  T1 = 273 K                      T2 = 273 + 27 = 300 ∴V1=20×2.82×273300×1=51.3241=51324 mLActual volume to be transferred into balloons = 51324 – 2820 mL = 48504 mL [∵ 2820 mL of H2 will remain in cylinder] Volume of one balloon =43πr3=43×227×2123∵r= diameter 2= 4851 mL = 4.851LNo. of balloons that can be filled up=485044851=9.999≈10