Integrated rate law

Question

The gas phase decomposition of hydrogen iodide at 700 K

HI(g)½ H₂(g) + ½ I₂(g)

is second order in HI with a rate constant of 1.20×10^-3 M^-1 s^-1.If the initial concentration of HI is 1.06 M, the concentration of HI will be  M after 2.08×10³ seconds have passed.

Answer 1

The second order rate equation is Rate = k[HI]². The integrated second order rate equation is

1/[HI] = kt + 1/[HI]_0. Substituting the give information, the equation becomes

1/[HI] = 1.20 x 10^-3 M^-1s^-1 x 2.08 x 10³ s + 1/1.06 M.

1/[HI] = 3.44 M^-1

[HI] = 0.291 M