Question

Equimolar concentration of $H_2$ & $I_2$ are heated equilibrium in a $1$ liter flask at equilibrium the forward and backward rate constants are found to be equal what percentage of initial concentration of $H_2$ has reached at equilibrium

• A. $33\%$$
• B. $66\%$$
• C. $50\%$$
• D. $40\%$$

Answer 1

The correct option is A $33\%$$

Reaction is --->

if Initially we have 100 % of [H2] then, we can assume that x % get reacted so 2x % of HI will be formed by the stoichiometry.

now, rate constant , k =

we also know,

where is forward rate constant and backward rate constant.

a/c to question,

so, k = 1 =

and also given, [H2] = [I2]

so, k = 1 =

1 = (2x)²/(100- x)²

2x = (100 - x)

x = 33.33 %

hence, answer is 33.33%