Potassium tetrahydroxozincate (II)

Tetrahydroxozincate
Tetrahydroxozincate
Are common
Systematic ; name	Potassium tetrahydroxozincate (II)
Chem. formula	K 2 [Zn (OH) 4 ]
Physical properties
condition	colorless (white) crystals
Molar mass	211.62 g / mol

Potassium tetrahydroxozincate (II) is an inorganic compound, a complex hydroxide of an alkali metal potassium and amphoteric metal of zinc with the formula K ₂ [Zn (OH) ₄ ], colorless (white) crystals, soluble in alkaline solutions; forms crystalline hydrate .

Getting

Dissolution of zinc oxide , hydroxide or chloride in a hot concentrated solution of potassium hydroxide :

{\mathsf {ZnO+2KOH+H_{2}O\ {\xrightarrow {90^{o}C}}\ K_{2}[Zn(OH)_{4}]}}

{\ displaystyle {\ mathsf {ZnO + 2KOH + H_ {2} O \ {\ xrightarrow {90 ^ {o} C}} \ K_ {2} [Zn (OH) _ {4}]}}}

{\mathsf {Zn(OH)_{2}+2KOH\ {\xrightarrow {}}\ K_{2}[Zn(OH)_{4}]}}

{\ displaystyle {\ mathsf {Zn (OH) _ {2} + 2KOH \ {\ xrightarrow {}} \ K_ {2} [Zn (OH) _ {4}]}}}

{\mathsf {ZnCl_{2}+4KOH\ {\xrightarrow {}}\ K_{2}[Zn(OH)_{4}]+2KCl}}

{\ displaystyle {\ mathsf {ZnCl_ {2} + 4KOH \ {\ xrightarrow {}} \ K_ {2} [Zn (OH) _ {4}] + 2KCl}}}

Physical Properties

Potassium tetrahydroxozincate (II) forms colorless (white) crystals.

It is soluble in alkaline aqueous and alcoholic solutions, in aqueous solutions it is completely hydrolyzed .

Forms a crystalline hydrate of the composition K ₂ [Zn (OH) ₄ ] • 2H ₂ O.

Chemical Properties

Anhydrous base is obtained by drying crystalline hydrate in vacuum :

{\mathsf {K_{2}[Zn(OH)_{4}]\cdot 2H_{2}O\ {\xrightarrow {87^{o}C,vacuum}}\ K_{2}[Zn(OH)_{4}]+2H_{2}O}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] \ cdot 2H_ {2} O \ {\ xrightarrow {87 ^ {o} C, vacuum}} \ K_ {2} [Zn (OH) _ {4}] + 2H_ {2} O}}}

Decomposes on heating:

{\mathsf {K_{2}[Zn(OH)_{4}]\ {\xrightarrow {>100^{o}C}}\ ZnO+2KOH+H_{2}O}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] \ {\ xrightarrow {> 100 ^ {o} C}} \ ZnO + 2KOH + H_ {2} O}}}

In dilute aqueous solutions, it decomposes:

{\mathsf {K_{2}[Zn(OH)_{4}]\ {\xrightarrow {}}\ Zn(OH)_{2}\downarrow +2KOH}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] \ {\ xrightarrow {}} \ Zn (OH) _ {2} \ downarrow + 2KOH}}}

It reacts differently with acids, depending on the concentration:

{\mathsf {K_{2}[Zn(OH)_{4}]+2HCl\ {\xrightarrow {}}\ 2KCl+Zn(OH)_{2}\downarrow +2H_{2}O}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] + 2HCl \ {\ xrightarrow {}} \ 2KCl + Zn (OH) _ {2} \ downarrow + 2H_ {2} O} }}

{\mathsf {K_{2}[Zn(OH)_{4}]+4HCl\ {\xrightarrow {}}\ 2KCl+ZnCl_{2}+4H_{2}O}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] + 4HCl \ {\ xrightarrow {}} \ 2KCl + ZnCl_ {2} + 4H_ {2} O}}}

Reacts with carbon dioxide from the air:

{\mathsf {K_{2}[Zn(OH)_{4}]+CO_{2}\ {\xrightarrow {}}\ K_{2}CO_{3}+Zn(OH)_{2}\downarrow +H_{2}O}}

{\ displaystyle {\ mathsf {K_ {2} [Zn (OH) _ {4}] + CO_ {2} \ {\ xrightarrow {}} \ K_ {2} CO_ {3} + Zn (OH) _ {2 } \ downarrow + H_ {2} O}}}

Literature

Lidin R. A. , Andreeva L. L. , Molochko V. A. Chemical properties of inorganic substances: Textbook. manual for universities - 3rd ed., Rev. - M .: Chemistry , 2000. - 480 p. - ISBN 5-7245-1163-0
<a href=" https://wikidata.org/wiki/Track:Q52153739 "> </a> <a href=" https://wikidata.org/wiki/Track:Q52153731 "> </a> <a href = " https://wikidata.org/wiki/Track:Q52153729 "> </a> <a href=" https://wikidata.org/wiki/Track:Q52153728 "> </a> <a href = " https://wikidata.org/wiki/Track:Q52153736 "> </a>

Tetrahydroxozincate
Are common
Systematic name	Potassium tetrahydroxozincate (II)
Chem. formula	K ₂ [Zn (OH) ₄ ]
Physical properties
condition	colorless (white) crystals
Molar mass	211.62 g / mol

Potassium tetrahydroxozincate (II)

Getting

Physical Properties

Chemical Properties

Literature

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