Дигидрат Оксалата магния

Description

Magnesium oxalate dihydrate is a crystalline hydrate of a salt of oxalic acid and magnesium, containing two molecules of water per formula unit. Like most alkaline earth metal oxalates, the compound has very low solubility in water, which is typical for this class of salts and determines its role in analytical chemistry as a reference sparingly soluble standard. Synonyms: magnesium oxalate, magnesium oxalate-2-hydrate, oxalic acid magnesium salt dihydrate.

The oxalate anion coordinates the magnesium ion bidentately through two oxygen atoms of the carboxyl groups - a structural feature common to the entire group of alkaline earth metal oxalates and determining their characteristically low solubility in water with noticeably better solubility in acidic media. The solubility values ​​given in the reference data (0.38–0.4 g/L in the range 25–92 °C) show that the solubility of the compound is weakly dependent on temperature - this distinguishes it from many other inorganic salts and simplifies the use of the substance as a stable solid-phase standard.

Basic Attributes

• CAS No.: 6150-88-5
• Chemical formula: C2H4MgO6
• Molecular weight: 148.35
• Exact weight: 147.986
• EU number: 208-932-1
• UNII: D674BHV95V
• DSSTox ID: DTXSID00210485
• PSA specifications: 82.3

Physico-chemical characteristics

• Density: 2.45 [CRC10]
• Melting point: 150°C
• Flash point: 188.8 °C
• Solubility in water: 0.38 ± 0.04 g/l at 25 °C, 0.4 g/l at 92 °C; solid phase form MgC2O4 2H2O [KRU93]

Scope of application

Used in analytical and preparative chemistry as a reagent and reference sample for sensitive chromatographic and analytical techniques where minimal background interference is important. It is used in research work on organic synthesis and cross-coupling reactions as a source of magnesium ions in a controlled, slightly soluble form, which is convenient for the dosed release of the metal ion in the reaction medium. The practically unchanged solubility of the compound in the temperature range of 25–92 °C (0.38–0.4 g/l) distinguishes it favorably from many other inorganic salts and simplifies the calculation of equilibrium concentrations of magnesium ion in aqueous systems when developing analytical methods.

Safety Information

Detailed data on hazard classification, transport codes and H/P phrases are not provided in the source. When working with the substance, they are guided by standard rules for handling inorganic salts of moderate toxicity - use of gloves and safety glasses, minimizing the formation of dust.

Storage and transportation conditions

Store in a tightly closed container in a dry place at room temperature. The crystalline hydrate form requires protection from excessive heating and drying, which can lead to partial loss of water of crystallization and a change in the physical properties of the powder. Data on the boiling point are not given in the source - the substance, like a typical inorganic salt, decomposes under strong heat before it reaches a boil. When working with small portions, it is recommended to first check the actual content of water of crystallization in a specific batch of the reagent, since the degree of hydration of oxalates can change slightly during long-term storage.