A 20 mL mixture of CO, `CH_4`, and Helium (He) gases is exploded by an electric discharge at room temperature with excess of oxygen. The volume contraction is found to be 13 mL. A further contraction of 14 mL occurs when the residual gas is treated wityh KOH solution. Find out the composition of the gaseous mixture in terms of volume percentage.

Explanation

`CO(g) + 1/2 O_(2)(g) rarr CO_(2)(g)`
`CH_(4)(g) + 2O_(2)(g) rarr CO_(2)(g) + 2H_(2)O(l)`
'x' is the volume of CO and y is+ the volume of `CH_(4)`
Thus, 1/2 x + y = 13 ........ (i)
x + y =14 ........ (ii)
By solving eq. (i) & (ii), we get
x = 2 cc , y = 12 cc
Thus, % `CH_(4) = 60 , % CO = 10 , % He = 30 `