The equilibrium concentrations for the reaction H ₂( g ) + I ₂( g ) 2 HI ( g ) at a constant temperature are recorded for two different experiments in the table below: Experiment [ H ₂] in M [ I ₂] in M [ HI ] in M 1 0.1 0.1 0.4 2 0.1 x 0.8 The value of the missing equilibrium concentration ' x ' is:

Step-by-step solution

For the reaction H ₂( g ) + I ₂( g ) 2 HI ( g ) , the equilibrium constant K_c is given by: K_c = [ HI ]^2 [ H ₂][ I ₂] Using the data from Experiment 1: K_c = (0.4)^2 (0.1)(0.1) = 0.16 0.01 = 16 Since the temperature is constant, K_c remains the same for Experiment 2. Substituting the values from Experiment 2 into the K_c expression: 16 = (0.8)^2 (0.1)(x) 16 = 0.64 0.1x 1.6x = 0.64 x = 0.4 M The missing concentration is 0.4 M . Answer: 0.4 M