At which points would the concentration of H2 lie on this graph:

Question

After a 2.0 mole sample of HI (g) is placed into an evacuated 1.0 L container at 700. K, the following reaction occurs: 

2 HI_(g) ↔ H_2(g)  + I_2(g)

The concentration of HI_(g) as a function of time is shown below.

Answer 1

Both H₂ and I₂ would appear any time after zero time. As soon as the reaction begins, HI begins to disappear, and both H₂ and I₂ begin to appear. So, I guess the answer would be that the concentration of H₂ lies at every point on the graph EXCEPT at zero time.