$k\,= \,\frac{{2.303}}{t}\,\,\log \,\,\frac{{{{[A]}_0}}}{{{{[A]}_t}}}$

$\log \frac{{{[A]}_{0}}}{{{[A]}_{t}}}=\frac{kt}{2.303}$  $=\frac{4.5\times {{10}^{-3}}\,{{\min }^{-1}}\times \,60\,\min }{2.303}$ $=0.11729$

$\log \frac{{{{[A]}_0}}}{{{{[A]}_t}}}\,\, = \,Antilog \,0.1172\,= \,1.310$

${[A]_t}\, = \,\frac{{{{[A]}_0}}}{{1.310}}\, = \,\frac{M}{{1.310}}\, = \,0.763\,M$

તબક્કો $2:1$ કલાક $(60 $ મિનિટ) પછી દરની ગણતરી

$60$ મિનિટ પછી દર $=k{{[A]}_{t}}$ $=4.5\times {{10}^{-3}}\,mi{{n}^{-1}}$ $\times 0.763\,M=$ $3.4354\times {{10}^{-3}}M\,mi{{n}^{-1}}$