A mixture of 10ml CH_(4), C_(2)H_(4) and C_(2) H_(2) has a vapour of 11.3 When30ml of oxygenare sparked together over a aqueous KOH, the volume contracts to 5.5ml and then disappears when pyrogallol is introduced. If volume are measured in the same conditions of pressure temperature and humidity, calculate the composition of the original mixture.

A mixture of 10ml CH_(4), C_(2)H_(4) and C_(2) H_(2) has a vapour of 1

1.	A mixture of 10ml CH_(4), C_(2)H_(4) and C_(2) H_(2) has a vapour of 11.3 When30ml of oxygenare sparked together over a aqueous KOH, the volume contracts to 5.5ml and then disappears when pyrogallol is introduced. If volume are measured in the same conditions of pressure temperature and humidity, calculate the composition of the original mixture.
Answer» Solution :Let the volume of `CH_(4)` at N.T.P. = x ml Let the volume of `C_(2) H_(4)` at N.T.P. = y ml Let the volume of `C_(2) H_(2)` at N.T.P. = z ml From question `x + y + z = 10 `.....(1) As we know that Weight of `CH_(4) + ` weight of `C_(2) H _(4) + ` weight of `C_(2) H _(2) = ` weight of MIXTURE `( 16x)/( 22400) + ( 28y )/( 22400) + ( 262)/( 22400) = ( 11.30)/( 11200) xx 10`.......(2) Now `underset( "x ml")(CH_(3)(g)) + underset(" 2x ml ")( 2O_(2)(g)) = CO_(2)(g) + 2H_(2)O(l)` `underset( "y ml ") ( C_(2) H_(4) ( g) ) + underset("3y ml ")(3O_(2)(g))HARR 2CO_(2)(g) + 2H_(2) O ( l )` `underset( " z ml") ( C_(2) H_(2)(g))+underset((5)/(2)Z ml )( (5)/(2) O_(2)(g) ) hArr 2CO_(2)(g) + H_(2)O(l)` Total volume of oxygen USED up in the reaction ` = ( 2x + 3y + ( 5)/( 2)) ml` But from question, Total volume of oxygen used up `= 30 - 5.5 = 24.5 ml` `:. 2x + 3y + ( 5)/(2) z = 24.5 `.......(3) Solving EUQATION (1), ( 2) and ( 3) we get x = 4,y = 3, z = 3 `:. CH_(4) = 4ML, C_(2) H _(4) = 3ml , C_(2) H_(2) = 3ml`