Oxalate
Overview
Oxalate is the dianion with formula C2O42− also written (COO)22−. Either name is often used for derivatives, such as disodium oxalate
, (Na+)2C2O42−, or an ester
of oxalic acid (such as dimethyl oxalate, (CH3)2C2O4. Oxalate also forms coordination compounds where it is sometimes abbreviated as ox.
Many metal ions form insoluble precipitates with oxalate, a prominent example being calcium oxalate
, the primary constituent of the most common kind of kidney stone
s.
The dissociation of proton
s from oxalic acid
proceeds in a stepwise manner as for other polyprotic acids.
Disodium oxalate
Disodium oxalate, often called simply sodium oxalate, is a sodium salt of oxalic acid with the molecular formula Na2C2O4. It is usually a white, crystalline, odorless powder, that decomposes at 250–270 °C....
, (Na+)2C2O42−, or an ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
of oxalic acid (such as dimethyl oxalate, (CH3)2C2O4. Oxalate also forms coordination compounds where it is sometimes abbreviated as ox.
Many metal ions form insoluble precipitates with oxalate, a prominent example being calcium oxalate
Calcium oxalate
Calcium oxalate is a chemical compound that forms needle-shaped crystals, known in plants as raphides. A major constituent of human kidney stones, the chemical is also found in beerstone, a scale that forms on containers used in breweries...
, the primary constituent of the most common kind of kidney stone
Kidney stone
A kidney stone, also known as a renal calculus is a solid concretion or crystal aggregation formed in the kidneys from dietary minerals in the urine...
s.
The dissociation of proton
Proton
The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....
s from oxalic acid
Oxalic acid
Oxalic acid is an organic compound with the formula H2C2O4. This colourless solid is a dicarboxylic acid. In terms of acid strength, it is about 3,000 times stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate , is a chelating agent for metal cations...
proceeds in a stepwise manner as for other polyprotic acids.
Unanswered Questions
