Degree of dissociation `(alpha)` `alpha` are the number of moles which are dissociating from 1 mole of given reactants and gas density measurements can be used to determine the degree of dissociatin. Let us take a general case where one molecule of a substance A splits up into n molecules of A(g) on heating i.e., `A_(n)(g)hArrnA(g)` `t=0a` `t =t_(eq)a-x nx " "alpha=x/aimpliesx=a alpha` `a-a alpha n a alpha` Total number of Moles `=a-a alpha +n a alpha``=[1+(n-1)alpha]a` Observed molecular weight of molar mass of the mixture `M_("mixture")=(M_(A_(n)))/([1+(n-1)alpha]),M_(A_(n))=` Molar mass of `A_(n)` A sample of mixture A(g), B(g)and C(g) under equlibrium has a mean molecular weight (observed) of 80. The equlibrium is `A(g)hArrB(g)+C(g)` (Mol wt =100)`" "` (Mol. wt=60)`" "` (Mol. wt=40)Calculate the Degree of dissociation for given reaction.A. `0.25`B. `0.5`C. `0.75`D. `0.8`