A mixture of `SO_(3), SO_(2)` and `O_(2)` gases is maintained in a `10 L` flask at a temperature at which the equilibrium constant for the reaction is `100`:
`2SO_(2)(g)+O_(2)(g)hArr2SO_(3)(g)`
a. If the number of moles of `SO_(2)` and `SO_(3)` in the flask are equal. How many moles of `O_(2)` are present?
b. If the number of moles of `SO_(3)` in flask is twice the number of moles of `SO_(2)`, how many moles of oxygen are present?

Explanation

` 2 SO_(2) (g) + O_(2) (g) hArr 2 SO_(3) , " " K_(c) = ([SO^(2)])/([SO_(2)]^(2)[O_(2)] = 100)(Given)`
(a) As ` [ SO_(3)] = [ SO_(2)] , :. 100 = 1/([O_(2)]) or [O_(2)] = 1/ 100 molL^(-1)`
`:. O_(2) " present in 10 litre " = 1/100 xx 10 = 0*1 ` mole
(b) If ` [ SO_(3) ] = 2 [ SO_(2)] , i.e, ([SO_(3)])/([ SO_(2)] )= 2 " then " 100 = 4/ ([O_(2)] ) or [O_(2)] = 4/100 "mol"L^(-1)`
` :. O_(2) " present in 10 litre " = 4/100 xx 10 = 0*4` mole