Potassium Chromate (K2CrO4)-Powder

Characteristic

Potassium chromate is the inorganic compound with the formula (K₂CrO₄). This yellow solid is the potassium salt of the chromate anion.

Chemical formula：K₂CrO₄

Molar mass：194.189 g·mol⁻¹

Appearance：Yellow powder

Odor：odorless

Density：2.7320 g/cm³

Melting point：968 °C (1,774 °F; 1,241 K)

Boiling point：1,000 °C (1,830 °F; 1,270 K)

Solubility in water：62.9 g/100 mL (20 °C)

                                 75.1 g/100 mL (80 °C)

                                 79.2 g/100 mL (100 °C)

Solubility：insoluble in alcohol

Magnetic susceptibility (χ)：−3.9·10⁻⁶ cm³/mol

Refractive index (nD)：1.74

Crystal structure：rhombic

Application

Unlike the less expensive sodium salt, potassium salt is mainly used for laboratory work in situations where an anhydrous salt is required. It is as an oxidizing agent in organic synthesis. It is used as in qualitative inorganic analysis, e.g. as a colorimetric test for silver ion. It is also used as an indicator in precipitation titrations with silver nitrate and sodium chloride (they can be used as standard as well as titrant for each other) as potassium chromate turns red in the presence of excess of silver ions.