Magnesium oxalate

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

according to guideline

Guideline:

other: no guideline available (publication data)

Principles of method if other than guideline:

- Principle of test:
- Short description of test conditions: Combined thermal analysis was used to establish the dissociation steps for the hydrated oxalate of magnesium.
- Parameters analysed / observed:

GLP compliance:

not specified

Type of method:

differential scanning calorimetry

Decomposition:

yes

Remarks:

Decomposition of the anhydrous form with loss of CO and CO2

Decomp. temp.:

>= 420 - <= 620 °C

Dehydration begins at 190-220°C (first dehydration) and ends at 280-340°C (second dehydratation) depending on the heating rate and from the weight changes, it is obvious that the endothermic reaction occurs.

MgC204,- 2 H2O = MgC2O4, + 2 H2O

On further heating, it appears from the DTA curves that three reactions overlap in the temperature range 420-620°C. At the end of these reactions active magnesia is produced and the weight loss corresponds to the removal of one mole of CO and one mole of CO2.

Anhydrous dissociated to the carbonate. For magnesium salt, at low heating rates, this step is accompanied by dissociation of MgCO3 to MgO.

Conclusions:

The test item decomposes from 420 to 620 °C.
Dehydration of the hydrated form begins at 190-220°C and ends at 280-340°C.
After decomposition, at the end of these reactions active magnesia is produced and the weight loss corresponds to the removal of one mole of CO and one mole of CO2.

Description of key information

The test item decomposes from 420 to 620 °C.

Dehydration of the hydrated form begins at 190-220°C and ends at 280-340°C.

After decomposition, at the end of these reactions active magnesia is produced and the weight loss corresponds to the removal of one mole of CO and one mole of CO2.