For the reaction:
2H$_2$O$_2$ $\xrightarrow{I^-}$ 2H$_2$O + O$_2$
Given mechanism:
(I) H$_2$O$_2$ + I$^-$ → H$_2$O + IO$^-$ (slow)
(II) H$_2$O$_2$ + IO$^-$ → H$_2$O + I$^-$ + O$_2$ (fast)
(1) Write rate law for the reaction.
(2) Write the overall order and molecularity of the reaction.