Passage VII

Consider the following reaction:

At chemical equilibrium, the formation of hydrogen iodide gas (HI) occurs at the same rate as the formation of hydrogen (H2) and iodine (I2) gases.

At equilibrium, the equilibrium constant, (Keq), is the ratio of the square of the HI concentration ([HI]) to the product of the concentrations of H2 and I2. The table below shows the data collected while varying either the temperature or the initial reactant concentrations.

40. Based on the information in the table, if the scientist had repeated the experiment at 400℃ and started with 2.0 mol L each of H2 and I2, the final concentration of HI would be closest to:

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

By comparing trail 3 and trail 7, we can see that the higher the initial concentration, the higher the Final [HI]. So when both Initial [H2] and Initial [I2] are 2.0 mol/L, the corresponding Final [HI] should be greater than 1.584 mol/L, so choose J