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[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

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[ACTION NAME]

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# Your action step 2

# Your action step 3

...

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system
Organic extractant (toluene) does not mix with aqueous solutions and is tinted violet by iodine. $\mathrm{Na}_{2} \mathrm{CO}_{3}$ can detect $\mathrm{H}_{2} \mathrm{SO}_{4}$ and $\mathrm{KI}+\mathrm{H}_{2} \mathrm{SO}_{4}$ by gas evolution, as well as barium and silver nitrates by the formation of white precipitates.

Sodium nitrite with diluted sulfuric acid causes no visible changes, whereas when reacting with $\mathrm{KI}+\mathrm{H}_{2} \mathrm{SO}_{4}$, it releases $\mathrm{I}_{2}$, which colors toluene violet.

\[ 
\begin{aligned}
& \mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{SO}_{4}=\mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2} \uparrow \\
& \mathrm{AgNO}_{3}+\mathrm{KI}=\mathrm{Agl} \downarrow+\mathrm{KNO}_{3} \\
& 2 \mathrm{AgNO}_{3}+\mathrm{Na}_{2} \mathrm{CO}_{3}=\mathrm{Ag}_{2} \mathrm{CO}_{3} \downarrow+2 \mathrm{NaNO}_{3} \\
& \mathrm{Ag}_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{SO}_{4}=\mathrm{Ag}_{2} \mathrm{SO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2} \uparrow \\
& \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}+\mathrm{H}_{2} \mathrm{SO}_{4}=\mathrm{BaSO}_{4} \downarrow+2 \mathrm{HNO}_{3} \\
& \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}+\mathrm{Na}_{2} \mathrm{CO}_{3}=\mathrm{BaCO}_{3} \downarrow+2 \mathrm{NaNO}_{3} \\
& \mathrm{BaCO}_{3}+\mathrm{H}_{2} \mathrm{SO}_{4}=\mathrm{BaSO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2} \uparrow \\
& 2 \mathrm{NaNO}_{2}+2 \mathrm{H}_{2} \mathrm{SO}_{4}+2 \mathrm{KI}=2 \mathrm{NO}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{I}_{2}+\mathrm{K}_{2} \mathrm{SO}_{4}+\mathrm{Na}_{2} \mathrm{SO}_{4} \\
& 2 \mathrm{NaNO}_{2}+3 \mathrm{H}_{2} \mathrm{SO}_{4}+4 \mathrm{KI}=\mathrm{N}_{2} \mathrm{O}+3 \mathrm{H}_ {2} \mathrm{O}+2 \mathrm{I}_{2}+2 \mathrm{~K}_ {2} \mathrm{SO}_{4}+\mathrm{Na}_{2} \mathrm{SO}_{4} \\
& 2 \mathrm{NaNO}_{2}+4 \mathrm{H}_{2} \mathrm{SO}_{4}+6 \mathrm{KI}=\mathrm{N}_{2}+4 \mathrm{H}_{2} \mathrm{O}+3 \mathrm{I}_{2}+3 \mathrm{~K}_{2} \mathrm{SO}_{4}+\mathrm{Na}_{2} \mathrm{SO}_{4}
\end{aligned}
\]

Barium and silver carbonates precipitates are white, but the latter dissolves in sulfuric acid $\left(\mathrm{Ag}_{2} \mathrm{SO}_{4}\right.$ precipitates only from concentrated solutions), while the former turns into barium sulfate.

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