For the reaction
$$5Br^- (aq) + BrO_3^- (aq) + 6H^+ (aq) \rightarrow 3Br_2 (aq) + 3H_2O (l)$$
the rate expression was found to be $$-\frac{d[BrO_3^-]}{dt} = k[Br^-][H^+]^2[BrO_3^-]$$.
Which of the following statements is are correct?
I. Doubling the initial concentration of all the reactants will increase the reaction rate by a factor of 8
II. Unit of rate constant of the reaction in a buffer solution is $$\text{min}^{-1}$$
III. Doubling the concentration of all the reactants at the same time will increase the reaction rate by a factor of 16
IV. Rate of conversion of $$BrO_3^-$$ and rate of formation of $$Br^-$$ are the same