Potassium selenate

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Potassium selenate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.029.286
EC Number 232-214-7
RTECS number VS6600000
Properties
K
2
SeO
4
Molar mass 221.2 g/mol[1]
Appearance colorless crystals
hygroscopic
Odor odorless
Density 3.07 g/cm3[2]
1.07 g/ml (0 °C)
1.11 g/ml (20 °C)
1.22 g/ml (100 °C)
1.539
Structure
orthorhombic
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Other anions
Potassium sulfate
Other cations
Sodium selenate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium selenate, K
2
SeO
4
, is an odorless, white solid that forms as the potassium salt of selenic acid. It is used in photography.

Preparation[edit]

Potassium selenate is produced by the reaction of selenium trioxide and potassium hydroxide.

SeO3 + 2 KOH → K2SeO4 + H2O

Alternatively, it can be made by reacting selenous acid with potassium hydroxide, and then oxidizing the resulting potassium selenite with bromine.[3]

H2SeO3 + 2 KOH → K2SeO3 + 2 H2O
K2SeO3 + 2 KOH + Br2 → K2SeO4 + 2 KBr + H2O

References[edit]