Explain the terms rate determining step and reaction intermediate.

For a reversible reaction, $\mathrm{A}\rightleftharpoons \mathrm{B}$, which one of the following statement is wrong from the given energy profile diagram?

The reaction $2 \mathrm{A}+{\mathrm{B}}_2\to 2\mathrm{AB}$ is an elementary reaction.

For a certain quantity of reactants, if the volume of the reaction vessel is reduced by a factor of $3,$ the rate of the reaction increases by a factor of _____ . (Round off to the Nearest Integer).

The reaction rate for the reaction

${\left[{\mathrm{PtCl}}_4\right]}^{2-}+{\mathrm{H}}_2\mathrm{O}\rightleftharpoons {\left[\mathrm{Pt}\left({\mathrm{H}}_2\mathrm{O}\right){\mathrm{Cl}}_3\right]}^{-}+{\mathrm{Cl}}^{-}$

was measured as a function of concentrations of different species. It was observed that

$\frac{-\mathrm{d}\left[{\left[{\mathrm{PtCl}}_4\right]}^{2-}\right]}{\mathrm{dt}}=4.8\times {10}^{-5}\left[{\left[{\mathrm{PtCl}}_4\right]}^{2-}\right]-2.4\times {10}^{-3}\left[{\left[\mathrm{Pt}\left({\mathrm{H}}_2\mathrm{O}\right){\mathrm{Cl}}_3\right]}^{-}\right]\left[{\mathrm{Cl}}^{-}\right]$

where square brackets are used to denote molar concentrations. The equilibrium constant

${\mathrm{K}}_{\mathrm{c}}=X$(Nearest integer)

Value of $\frac{1}{X} is$ (question is modified.)