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247537

Sigma-Aldrich

Oxalic acid dihydrate

ACS reagent, ≥99%

Synonym(s):

Ethanedioic acid dihydrate

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About This Item

Linear Formula:
HO2CCO2H · 2H2O
CAS Number:
Molecular Weight:
126.07
Beilstein:
3679436
EC Number:
MDL number:
UNSPSC Code:
12352100
eCl@ss:
39021701
PubChem Substance ID:
NACRES:
NA.21

grade

ACS reagent

Quality Level

vapor density

4.4 (vs air)

vapor pressure

<0.01 mmHg ( 20 °C)

Assay

≥99%
99.5-102.5% (ACS specification)

form

solid

impurities

H2SO4, passes test (darkened)
≤0.001% N compounds
≤0.005% insolubles

ign. residue

≤0.01%

mp

104-106 °C (lit.)

anion traces

chloride (Cl-): ≤0.002%
sulfate (SO42-): ≤0.005%

cation traces

Ca: ≤0.001%
Fe: ≤2 ppm
heavy metals: ≤5 ppm (by ICP-OES)

SMILES string

[H]O[H].[H]O[H].OC(=O)C(O)=O

InChI

1S/C2H2O4.2H2O/c3-1(4)2(5)6;;/h(H,3,4)(H,5,6);2*1H2

InChI key

GEVPUGOOGXGPIO-UHFFFAOYSA-N

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General description

Oxalic acid dihydrate is a promising candidate as a phase change material (PCM) for use in thermal energy storage (TES) technology due to its high heat of fusion and energy storage density/price ratio in comparison to other salt hydrates PCMs.

Application

Oxalic acid dihydrate may be used:
  • As a catalyst in the preparation of tetrahydroquinoline derivatives via imino Diels-Alder reaction.
  • As a homogeneous catalyst in the preparation of highly functionalized piperidines via multi-component reaction.
  • As an oxidant for the formation of triazolinediones from corresponding urazoles and bisurazoles via oxidation.
  • In the transformation of thiols to nitrosothiols by reacting with sodium nitrite.

Pictograms

CorrosionExclamation mark

Signal Word

Danger

Hazard Statements

Hazard Classifications

Acute Tox. 4 Dermal - Acute Tox. 4 Oral - Eye Dam. 1

Storage Class Code

11 - Combustible Solids

WGK

WGK 1

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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Effects of sodium chloride on the thermal behavior of oxalic acid dihydrate for thermal energy storage
Han L, et al
Applied Energy, 185, 762-767 (2017)
An Efficient Method for Production and Storage of Unstable S-Nitrosothiols Under Mild and Heterogeneous Condition with Sodium Nitrite and Oxalic Acid Dihydrate.
Zolfigol MA, et al.
Synthetic Communications, 29(13), 2277-2280 (1999)
One-pot five-component synthesis of highly functionalized piperidines using oxalic acid dihydrate as a homogenous catalyst.
Sajadikhah SS, et al.
Chinese Chemical Letters = Zhongguo Hua Xue Kuai Bao, 23(5), 569-572 (2012)
A Convenient Method for the Oxidation of Urazoles to Their Corresponding Triazolinediones Under Mild and Heterogeneous Conditions with Sodium Nitrite and Oxalic Dihydrate.
Zolfigolo MA and Mallakpour SE.
Synthetic Communications, 29(22), 4061-4069 (1999)
Imino Diels-Alder reactions catalyzed by oxalic acid dihydrate. Synthesis of Tetrahydroquinoline derivatives.
Nagarajan R and Perumal PT.
Synthetic Communications, 31(11), 1733-1736 (2001)

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