The composition of the equilibrium mixture (`Cl_(2)` `2Cl`) , which is attained at `1200^(@)C`, is determined by measuring the rate of effusion through a pin hole. It is observed that a `1.80 mm Hg` pressure, the mixture effuses `1.16 times` as fact as krypton effuses under the same conditions. Calculate the fraction of chlorine molecules dissociated into atoms (atomic weight of `Kr` is `84`).

Explanation

Accoring to Graham's law of diffusion
`(gamma_mix)/(gamma_Kr) =sqrt(((M_(Kr))/(M_(mix))))`
or `1.16 = sqrt(((84)/(M))) (P_(1)=P_(2))`
` M =62.425`
For `{:(CI_(2)hArr,2CI),(1,0),((1-alpha),2alpha):}`
`("Normal mo1 wt")/("Exp mol wt") = 1 + alpha`
`(71)/(62.425) = 1 +alpha`
`alpha = 0.137 or 13.7%` .