A student forgot to add the reaction mix | Class 11 Chemistry Chapter States of Matter, States of Matter NCERT Solutions

Question:

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:

Let the volume of  air in the  flask at 27°C be V1 & that of the same amount of the gas at 477°C be V2.

According to charle’s law

V2/T2  =  V1/ T1   …………………(1)

NOW  volume of gas expelled out = V2 – V1, THEN

Fraction of the gas expelled out = (V2 – V1 ) / V2 = 1- (V1/ V2)     …………….(2)

Also from equation (1)  V1/ V2 = T1/ T2   …………..(3)

Substituting the values of (3) in (2), we get

Fraction of the air expelled  = 1- T1/ T2 = (T2 – T1)/ T2

 = 750- 300 /750 = 0.6

Hence, fraction of air expelled out is 0.6 or 3/5 th


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Comments

  • Oj
  • 2018-08-30 20:22:19

Why did you do V2 - V1 and not V1-V2 as v1 has more volume than v2???


  • Riya Pandey
  • 2018-08-28 20:41:39

Thank you


Comment(s) on this Question

Welcome to the NCERT Solutions for Class 11 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 11: A student forgot to add the reaction mixture to the round bottomed flask at 27 °C but instead he....