Equilmolar concentrations of H_(2) and I_(2) are heated to equilibrium in a 2 litre flask . At equilibrium , the forward and the backward rate constants are found to be equal . What percentage of intial concentration of H_(2) has reacted at equilibrium ?

Equilmolar concentrations of H_(2) and I_(2) are heated to equilibrium

1.	Equilmolar concentrations of H_(2) and I_(2) are heated to equilibrium in a 2 litre flask . At equilibrium , the forward and the backward rate constants are found to be equal . What percentage of intial concentration of H_(2) has reacted at equilibrium ?
Answer» `33 %` `66 %` `50%` `40%` Solution :`{:(,H_(2)(g),+,I_(2) (g),hArr,2 HI(g)), (" Intial",1 "mol",,1 "mol",,0),("At eqm.",1-X,,1-x,,2x),("Molar conc.",(1-x)/2,,(1-x)/2,,(2x)/2"mol"L^(-1)),(,,,,,=x):}` ` K= (x^(2))/((1-x)/2 xx (1-x)/2 )=(4 x^(2))/(1-x)^(2) approx4x^(2)` But `K= (k_(f))/(k_(b))=1` `:. 4"" x^(2)=1 or x^(2) = 1//4 or x = 1//2 , i.e., 50%`