1.475-g sample containing ${\mathbf{NH}}_{\mathbf{4}}\mathbf{Cl}\mathbf{(}\mathbf{FM}\mathbf{53}\mathbf{.}\mathbf{491}\mathbf{)}\mathbf{,}{\mathbf{K}}_{\mathbf{2}}{\mathbf{CO}}_{\mathbf{3}}$(FM 138.21), and inert ingredients was dissolved to give 0.100 L of solution. A 25.0-mL aliquot was acidified and treated with excess sodium tetraphenylborate,${\mathbf{Na}}^{\mathbf{+}}\mathbf{B}\mathbf{(}{\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}{\mathbf{)}}_{\mathbf{4}}^{\mathbf{-}}$, to precipitate${\mathbf{K}}^{\mathbf{+}}$and

${\mathbf{NH}}_{\mathbf{4}}^{\mathbf{+}}$ions completely:

$$\begin{gathered} \mathbf{(}{\mathit{C}}_{\mathbf{6}}{\mathit{H}}_{\mathbf{5}}{\mathbf{)}}_{\mathbf{4}}{\mathit{B}}^{\mathbf{-}}\mathbf{+}{\mathit{K}}^{\mathbf{+}}\mathbf{\to }\mathbf{(}{\mathit{C}}_{\mathbf{6}}{\mathit{H}}_{\mathbf{5}}{\mathbf{)}}_{\mathbf{4}}\mathit{B}\mathit{K}\mathbf{\left(}\mathit{s}\mathbf{\right)} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathit{F}\mathit{M}\mathbf{358}\mathbf{.}\mathbf{33} \\ \mathbf{(}{\mathit{C}}_{\mathbf{6}}{\mathit{H}}_{\mathbf{5}}{\mathbf{)}}_{\mathbf{4}}{\mathit{B}}^{\mathbf{-}}\mathbf{+}\mathit{N}{\mathit{H}}_{\mathbf{4}}^{\mathbf{+}}\mathbf{\to }\mathbf{(}{\mathit{C}}_{\mathbf{6}}{\mathit{H}}_{\mathbf{5}}{\mathbf{)}}_{\mathbf{4}}\mathit{B}\mathit{N}{\mathit{H}}_{\mathbf{4}}\mathbf{\left(}\mathit{s}\mathbf{\right)} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathit{F}\mathit{M}\mathbf{337}\mathbf{.}\mathbf{27} \end{gathered}$$

The resulting precipitate amounted to 0.617 g. A fresh 50.0-mL aliquot of the original solution was made alkaline and heated to drive off all the${\mathbf{NH}}_{\mathbf{3}}\mathbf{.}$

$\mathit{N}{\mathit{H}}_{\mathbf{4}}^{\mathbf{+}}\mathbf{+}\mathit{O}{\mathit{H}}^{\mathbf{-}}\mathbf{\to }\mathit{N}{\mathit{H}}_{\mathbf{3}}\mathbf{\left(}\mathit{g}\mathbf{\right)}\mathbf{+}{\mathit{H}}_{\mathbf{2}}\mathit{O}$

It was then acidified and treated with sodium tetraphenylborate to give 0.554 g of precipitate. Find the weight percent of${\mathbf{NH}}_{\mathbf{4}}\mathbf{Cl}$and${\mathbf{K}}_{\mathbf{2}}{\mathbf{CO}}_{\mathbf{3}}$in the original solid.

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