A student forgot to add the reaction mixture to the round bottomed open flask at 27°C and put it on the flame. After a lapse of time, he realized his mistake, using a pyrometer he found the temperature of the flask was 477°C. What fraction of air would have been expelled out?

A student forgot to add the reaction mixture to the round bottomed ope

1.	A student forgot to add the reaction mixture to the round bottomed open flask at 27°C and put it on the flame. After a lapse of time, he realized his mistake, using a pyrometer he found the temperature of the flask was 477°C. What fraction of air would have been expelled out?
Answer» <p><span>Initial mole of air in flask = n1</span></p><p><span>Temperature = 21 + 273 = 300 K</span></p><p><span>Final mole of air in flask = n2</span></p><p><span>Temperature = 477 + 273 = 750 K</span></p><p><span>The volume and pressure remains constant, thus, n1T1= n2T2</span></p><p><span>n2= n1x 300/750 = 2/5 n1</span></p><p><span>Thus, air expelled out on heating = n1- n2= n1- (2/5) n1= 3/5 n1</span></p><p><span>orfraction of air expelled = 3/5.</span></p>