A student forgot to add the reaction mixture to the round bottomed flask at 27 ∘C but instead he/she placed the flask on the flame. After a lapse of time, he realized his mistake, and using a pyrometer he found the temperature of the flask was 477 ∘C. What fraction of air would have been expelled out?
Answer : Option AExplaination / Solution:
n1/n2=T2/T1 =0.4 so fraction of air expelled out =1-0.6=0.4.
Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius 10 m, mass 100 kg is filled with helium at 1.66 bar at27∘C. (Density of air = 1.2 kg m-3 and R = 0.083 bar dm3K−1mol−1.
Answer : Option BExplaination / Solution: Volume of balloon,V=4/3(3.14)r3 =4187 m3Mass of displaced air,m=V × δ =4187 x 1.2=5024.4 kg Temperature,T=300 K Moles of gas present,n=PV/RT=279.1 × 103 moles Mass of helium=279.1 ×103 x 4=116.4 kg Mass of filled balloon,m'=100+1116.4=1216.4 kg Payload=m-m'=3811.1 kg
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Scored Mark :
Mark for Correct Answer : 1
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