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?
Let the volume of the round bottomed flask be V.
Then, the volume of air inside the flask at 27∘C is V.
Now,
V1=V
T1=27∘C=300 K ,V2=?
T2=477∘C=750 K
According to Charles's law,
V1T1=V2T2
⇒V2=V1T2T2
=750 V300
=2.5 V
Therefore, volume of air expelled out = 2.5V–V=1.5V
Hence, fraction of air expelled out =1.5 V2.5 V=35