# Describe isolation method in determination of rate law & order of reaction

The tedious step in reaction mixtures is determining its kinetic mechanism (rate law and order) which are performed using the best method of Isolation techniques. The isolation technique is proceeded with reducing the concentration of reactant to the smaller than when comparing with other reactant, by using this all the concentrations with zero,first and second order kinetics plot are interpreted using concentration-time data except the reactant with constant conditions.

For example the conversion of methyl bromide to methanol using substitution reaction is expressed below for quick grasping of the concept,

$C{H}_{3}Br\left(aq\right)+O{H}^{-}\left(aq\right)\to C{H}_{3}OH\left(aq\right)+B{r}^{-}\left(aq\right)\phantom{\rule{0ex}{0ex}}r=k\left[C{H}_{3}Br\right]\left[O{H}^{-}\right]\phantom{\rule{0ex}{0ex}}r={k}_{obs}\left[C{H}_{3}Br\right]\phantom{\rule{0ex}{0ex}}{k}_{obs}=k\left[O{H}^{-}\right]\phantom{\rule{0ex}{0ex}}{k}_{obs}=k[O{H}^{-}{]}^{b}\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}Theintreprationofthedataareperformedu\mathrm{sin}gtheequationbelow,\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\mathrm{ln}{k}_{obs}=\mathrm{ln}k+b\mathrm{ln}[O{H}^{-}]$

The slope and intercept values are used in determination of the isolation rate of the molecules, by using the interpreted data (concentration) the order of reaction are expressed below,

$-\frac{1}{a}\frac{d\left[A\right]}{dt}=k\left[A{]}^{n}\phantom{\rule{0ex}{0ex}}{\int}_{\left[{A}_{o}\right]}^{\left[A\right]}\right[A{]}^{-n}d\left[A\right]=-ak{\int}_{0}^{t}dt\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}onintegratingweget,\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\frac{1}{-n+1}\left[\right[A{]}^{-n+1}{]}_{\left[{A}_{o}\right]}^{\left[A\right]}=-ak[t{]}_{0}^{t}\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\Rightarrow \frac{1}{n-1}\{\frac{1}{[A{]}^{n-1}}-\frac{1}{[{A}_{o}{]}^{n-1}}\}=akt$

Regards.

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