Reaction Mechanisms and Rate Law Practice Test

In aqueous solution, a student proposes the following mechanism for the reaction $\mathrm{S_2O_8^{2-}(aq)+2I^-(aq)\rightarrow I_2(aq)+2SO_4^{2-}(aq)}$:

Step 1 (slow): $\mathrm{S_2O_8^{2-}+I^-\rightarrow SO_4^{2-}+SO_4^-+I}$

Step 2 (fast): $\mathrm{SO_4^-+I^-\rightarrow SO_4^{2-}+I}$

Step 3 (fast): $\mathrm{I+I\rightarrow I_2}$

Which rate law is implied by the mechanism?

A proposed mechanism for the reaction $\mathrm{H_2(g)+I_2(g)\rightarrow 2HI(g)}$ is:

Step 1 (slow): $\mathrm{I_2 \rightarrow 2I}$

Step 2 (fast): $\mathrm{I + H_2 \rightarrow HI + H}$

Step 3 (fast): $\mathrm{H + I \rightarrow HI}$

Which rate law is implied by the mechanism?