Question

9 ml of mixture of methane in ethylene and exploded with 30 ml oxygen after cooling residual gas mixture was found to be 21 ml on treatment with another solution it was reduced to 7 ml what is the true for given mixture

Answer 1

The percentage of CH4 is 4ml.  

Let volume of CH4 be "a" and C2H4 be "b" .

As oxygen is in excess quantity.

Therefore reaction of methane and ethane write as

CH4 + 2O2 ---> CO2 + 2H2O.  

a 2a a (these are moles)And of ethylene as :

C2H4 + 3O2 ------> 2CO2   +   2H2O; b 3b 2

b. As after cooloing mixture was found 21 ml.

And it was teduced to 7 on treatment with NaOH therefore CO2 consumed by NaOH is 14 ml And equating moles of CO2 asa+ 2b = 14; we know that a+b=9 ; b = 5 ,Therefore a= 4 ans.