Some Basic Concepts Of Chemistry Question 81
Question: An ideal gaseous mixture of ethane $ (C _2H _5) $ and ethene $ (C _2H _4) $ occupies 28 litre at 1 atm and 273 K. The mixture reacts completely with 128 g $ O _2 $ to produce $ CO _2 $ and $ H _2O $ . Mole fraction at $ C _2H _6 $ in the mixture is:
Options:
A) 0.6
B) 0.4
C) 0.5
D) 0.8
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ C _2H _6+3.5O _2\xrightarrow{{}}2CO _2+3H _2O; $
$ C _2H _4+3O _2\xrightarrow{{}}2CO _2+2H _2O $ Let volume of ethane is x litre, $ 22.4\times 4=3.5x+3( 28-x ) $
$ \Rightarrow x=11.2 $ litre at constant T and P, $ V\propto n $ :
$ \Rightarrow $ Mole fraction of $ C _2H _6 $ in mixture $ =\frac{11.2}{28}=0.4 $
