Consider the reaction $3 \mathrm{I}^{-}+\mathrm{S}_2 \mathrm{O}_8^{2-} \longrightarrow \mathrm{I}_3^{-}+2 \mathrm{SO}_4^{2-}$, at a particular time t , $\frac{\mathrm{d}\left[\mathrm{SO}_4^{2-} ight]}{\mathrm{dt}}$ is $2.2 imes 10^{-2} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}$. What is…

Question

Consider the reaction $3 \mathrm{I}^{-}+\mathrm{S}_2 \mathrm{O}_8^{2-} \longrightarrow \mathrm{I}_3^{-}+2 \mathrm{SO}_4^{2-}$, at a particular time t , $\frac{\mathrm{d}\left[\mathrm{SO}_4^{2-}ight]}{\mathrm{dt}}$ is $2.2 	imes 10^{-2} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}$. What is the value of $\frac{\mathrm{d}\left[\mathrm{S}_2 \mathrm{O}_8^{2-}ight]}{\mathrm{dt}}$ ?

Aicharya · Accepted Answer

$3 \mathrm{I}^{-}+\mathrm{S}_2 \mathrm{O}_8^{2-} \longrightarrow \mathrm{I}_3^{-}+2 \mathrm{SO}_4^{2-}$
Rate of reaction $=-\frac{1}{3} \frac{\mathrm{~d}\left[\mathrm{I}^{-}\right]}{\mathrm{dt}}=-\frac{\mathrm{d}\left[\mathrm{~S}_2 \mathrm{O}_8^{2-}\right]}{\mathrm{dt}}=\frac{\mathrm{d}\left[\mathrm{I}_3^{-}\right]}{\mathrm{dt}}=\frac{1}{2} \frac{\mathrm{~d}\left[\mathrm{SO}_4^{2-}\right]}{\mathrm{dt}}$
Hence, $\frac{\mathrm{d}\left[\mathrm{S}_2 \mathrm{O}_8^{2-}\right]}{\mathrm{dt}}=\frac{1}{2} \frac{\mathrm{~d}\left[\mathrm{SO}_4^{2-}\right]}{\mathrm{dt}}$ $=\frac{1}{2} \times 2.2 \times 10^{-2}=1.1 \times 10^{-2} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~s}^{-1}$

Consider the reaction $3 \mathrm{I}^{-}+\mathrm{S}_2 \mathrm{O}_8^{2-} \longrightarrow \mathrm{I}_3^{-}+2…

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