Rhenic acid

Rhenic acid
Rhenic acid
Are common
Systematic ; name	Rhenic acid
Traditional names	Metarenic acid
Chem. formula	HReO 4
Physical properties
condition	colorless aqueous solution
Molar mass	251.21 g / mol
Classification
Reg. CAS number	13768-11-1
PubChem
Reg. EINECS number
Smiles
Inchi
RTECS
ChemSpider

Rhenium acid is an inorganic compound, an oxygen-containing acid with the formula HReO ₄ , exists only in aqueous solutions, forms perrenate salts.

Content

Getting

The effect of concentrated sulfuric acid on rhenium metal or rhenium (IV) oxide :

{\mathsf {2Re+7H_{2}SO_{4}\ {\xrightarrow {}}\ 2HReO_{4}+7SO_{2}\uparrow +6H_{2}O}}

{\ displaystyle {\ mathsf {2Re + 7H_ {2} SO_ {4} \ {\ xrightarrow {}} \ 2HReO_ {4} + 7SO_ {2} \ uparrow + 6H_ {2} O}}}

{\mathsf {2ReO_{2}+3H_{2}SO_{4}\ {\xrightarrow {}}\ 2HReO_{4}+3SO_{2}\uparrow +2H_{2}O}}

{\ displaystyle {\ mathsf {2ReO_ {2} + 3H_ {2} SO_ {4} \ {\ xrightarrow {}} \ 2HReO_ {4} + 3SO_ {2} \ uparrow + 2H_ {2} O}}}

The effect of concentrated hydrogen peroxide on metallic rhenium or rhenium (IV) oxide:

{\mathsf {2Re+7H_{2}O_{2}\ {\xrightarrow {}}\ 2HReO_{4}+6H_{2}O}}

{\ displaystyle {\ mathsf {2Re + 7H_ {2} O_ {2} \ {\ xrightarrow {}} \ 2HReO_ {4} + 6H_ {2} O}}}

{\mathsf {2ReO_{2}+3H_{2}O_{2}\ {\xrightarrow {}}\ 2HReO_{4}+2H_{2}O}}

{\ displaystyle {\ mathsf {2ReO_ {2} + 3H_ {2} O_ {2} \ {\ xrightarrow {}} \ 2HReO_ {4} + 2H_ {2} O}}}

Oxidation of rhenium (IV) oxide with chlorine :

{\mathsf {2ReO_{2}+3Cl_{2}+4H_{2}O\ {\xrightarrow {}}\ 2HReO_{4}+6HCl}}

{\ displaystyle {\ mathsf {2ReO_ {2} + 3Cl_ {2} + 4H_ {2} O \ {\ xrightarrow {}} \ 2HReO_ {4} + 6HCl}}}

Hydrolysis of rhenium (VII) fluoride :

{\mathsf {ReF_{7}+4H_{2}O\ {\xrightarrow {}}\ HReO_{4}+7HF}}

{\ displaystyle {\ mathsf {ReF_ {7} + 4H_ {2} O \ {\ xrightarrow {}} \ HReO_ {4} + 7HF}}}

Physical Properties

Rhenic acid exists only in aqueous solutions, the maximum concentration of 70%. The solutions are colorless or slightly yellowish.

It is a strong acid, p K _α = −1.25.

Chemical Properties

Concentration (evaporation in vacuo ) produces "solid rhenium acid":

{\mathsf {2HReO_{4}+H_{2}O\ {\xrightarrow {\tau ,90^{o}C,vacuum}}\ H_{4}Re_{2}O_{9}}}

{\ displaystyle {\ mathsf {2HReO_ {4} + H_ {2} O \ {\ xrightarrow {\ tau, 90 ^ {o} C, vacuum}} \ H_ {4} Re_ {2} O_ {9}}} }

With alkalis it forms perrenates :

{\mathsf {HReO_{4}+NaOH\ {\xrightarrow {}}\ NaReO_{4}\ +H_{2}O}}

{\ displaystyle {\ mathsf {HReO_ {4} + NaOH \ {\ xrightarrow {}} \ NaReO_ {4} \ + H_ {2} O}}}

It is a weak oxidizing agent :

{\mathsf {2HReO_{4}+7H[SnCl_{3}]+21HCl\ {\xrightarrow {}}\ 2Re\downarrow +7H_{2}[SnCl_{6}]+8H_{2}O}}

{\ displaystyle {\ mathsf {2HReO_ {4} + 7H [SnCl_ {3}] + 21HCl \ {\ xrightarrow {}} \ 2Re \ downarrow + 7H_ {2} [SnCl_ {6}] + 8H_ {2} O} }}

Literature

Chemical Encyclopedia / Editorial Board: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1995. - T. 4. - 639 p. - ISBN 5-82270-092-4 .
Lidin R.A. and other Chemical properties of inorganic substances: Textbook. manual for universities. - 3rd ed., Rev. - M .: Chemistry, 2000 .-- 480 p. - ISBN 5-7245-1163-0 .
Ripan R., Chetyanu I. Inorganic chemistry. Chemistry of metals. - M .: Mir, 1972. - T. 2. - 871 p.