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Potassium dichromate

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Identification
Molecular formula
K2Cr2O7
CAS number
7778-50-9
IUPAC name
dipotassium;dioxido(dioxo)chromium
State
State

At room temperature, potassium dichromate is in a solid state. It exists as crystalline powder, which is relevant for its handling and usage in various laboratory and industrial applications, especially considering its hygroscopic nature.

Melting point (Celsius)
398.00
Melting point (Kelvin)
671.00
Boiling point (Celsius)
500.00
Boiling point (Kelvin)
773.00
General information
Molecular weight
294.18g/mol
Molar mass
294.1840g/mol
Density
2.6760g/cm3
Appearence

Potassium dichromate appears as bright orange-red crystalline solid. It is odorless and forms as a crystalline powder which may look yellow-orange under certain lighting conditions. It is highly soluble in water and presents a significant visual contrast with many other substances due to its vivid color.

Comment on solubility

Solubility of Dipotassium Dioxido(dioxo)chromium

Dipotassium dioxido(dioxo)chromium, or K2CrO4, exhibits notable characteristics when it comes to its solubility in various solvents.

Solubility in Water

This compound is known for its **excellent solubility** in water. Its ionic nature allows it to dissociate readily, making it a highly soluble species. In aqueous solutions, it typically presents the following properties:

  • High solubility: K2CrO4 can dissolve in water at concentrations that are significant for various chemical applications.
  • Ionization: Upon dissolution, it ionizes to yield potassium ions (K+) and chromate ions (CrO42-).
  • Color Change: The solution is often yellow due to the presence of chromate ions, which can be visually striking.

Solubility in Organic Solvents

When it comes to organic solvents, the solubility of dipotassium dioxido(dioxo)chromium does not present the same favorable conditions:

  • Low solubility: The compound shows limited solubility in non-polar organic solvents, which is typical for ionic compounds.
  • Polar solvents: It may have varying solubility depending on the polarity of the organic solvent used, but generally, it dissolves poorly.

In summary, dipotassium dioxido(dioxo)chromium is significantly soluble in water but exhibits poor solubility in organic solvents. This characteristic makes it valuable in aquatic chemical processes and widely utilized in various applications, particularly in analytical chemistry and electrochemistry.

Interesting facts

Interesting Facts about Dipotassium Dioxido(dioxo)chromium

Dipotassium dioxido(dioxo)chromium is a fascinating compound with a rich chemical profile and a variety of applications. Here are some key points to consider:

  • Chemical Nature: This compound is a potassium salt of chromate and is often referred to by its systematic name, highlighting the presence of chromium in its +6 oxidation state. Chromium compounds are renowned for their vibrant colors, and this complex is no exception.
  • Oxidation States: Chromium plays a significant role in various oxidation states, but in this compound, its +6 oxidation state is particularly notable due to its high reactivity and potential for chromate ion interconversion.
  • Applications: Dipotassium dioxido(dioxo)chromium finds usage in various fields, including:
    • As a powerful oxidizing agent in synthetic chemistry.
    • In the preparation of chromium-based pigments.
    • In leather tanning processes, where chromium compounds enhance durability.
  • Environmental Impact: While chromium is essential in metallurgy, the presence of hexavalent chromium is a concern due to its toxicity and potential environmental hazards. Proper handling and disposal are critical to mitigate these risks.
  • Color Indicators: The vivid colors exhibited by chromium compounds, including various shades of green, are often utilized as color indicators in chemical experiments.

As a compound that straddles the line between utility and caution, dipotassium dioxido(dioxo)chromium remains a compelling subject for scientists and students alike.

Synonyms
POTASSIUM CHROMATE
Bipotassium chromate
Potassium chromate(VI)
Dipotassium chromate
Dipotassium monochromate
Chromate of potash
Chromate of potass
Neutral potassium chromate
Caswell No. 687
Chromic acid, dipotassium salt
Potassium chromate (K2(CrO4))
CCRIS 882
HSDB 1249
EINECS 232-140-5
UNII-5P0R38CN2X
EPA Pesticide Chemical Code 068301
5P0R38CN2X
Chromic acid (H2CrO4), dipotassium salt
KALI CHROMICUM
dipotassium dioxido(dioxo)chromium
POTASSIUM CHROMATE (VI)
DTXSID8064858
CHEBI:75249
EC 232-140-5
CHROMIC ACID (H2CRO4), DIPOTASSIUM SALT (1:2)
dipotassium chromate(2-)
Chromate of potassium
Pesticide Code 068301.
DTXCID4048062
232-140-5
7789-00-6
dipotassium;dioxido(dioxo)chromium
Tarapacaite
MFCD00011368
18453-57-1
Dipotassium chromate (K2CrO4)
51Cr-Potassium chromate
KALI CHROMICUM [HPUS]
Potassium chromate, ACS grade
POTASSIUM CHROMATE [HSDB]
POTASSIUM CHROMATE(VI) [MI]
AKOS015902665
AKOS025243253
NS00113210
Chromic acid (H2CrO4), potassium salt (1:2)
Q407939