Oxalic Acid Formula, Uses

Oxalic Acid Formula, Uses

Oxalic Acid: Oxalic acid is an organic compound with the formula C2H2O4. It is a colorless crystalline solid that forms a colorless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid.

It’s acid strength is much greater than that of acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate (C2O2−4), is a chelating agent for metal cations. Typically, oxalic acid occurs as the dihydrate with the formula C2H2O4·2H2O. It occurs naturally in many foods, but excessive ingestion of oxalic acid or prolonged skin contact can be dangerous.

Oxalic Acid Formula, Uses

Oxalic Acid Molar Mass

Oxalic acid, also called ethanedioic acid, a colorless, crystalline, toxic organic compound belonging to the family of carboxylic acids. Oxalic acid is widely used as an acid rinse in laundries, where it is effective in removing rust and ink stains because it converts most insoluble iron compounds into a soluble complex ion. For the same reason, it is the chief constituent of many commercial preparations used for removing scale from automobile radiators.

The formula of oxalic acid is (C2H2O4); its usual form is that of the crystalline hydrate, (COOH)2·2H2O. Known as a constituent of wood sorrel as early as the 17th century, oxalic acid was first prepared synthetically in 1776. It is manufactured by heating sodium formate in the presence of an alkali catalyst, by oxidizing carbohydrates with nitric acid, by heating sawdust with caustic alkalies, or by fermentation of sugar solutions in the presence of certain molds.

PubChem CID: 971
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Chemical Safety:
Laboratory Chemical Safety Summary (LCSS) Datasheet
Molecular Formula: C2H2O4 or (COOH)2 or HOOCCOOH

oxalic acid

ethanedioic acid




Molecular Weight: 90.03 g/mol
  • Modify:2019-11-09
  • Create:2004-09-16

Oxalic acid is an alpha,omega-dicarboxylic acid that is ethane substituted by carboxyl groups at positions 1 and 2. It has a role as a human metabolite, a plant metabolite, and an algal metabolite. It is conjugate acid of an oxalate(1-) and an oxalate.

Oxalic acid is an odorless white solid. Sinks and mixes with water. (USCG, 1999)

A strong dicarboxylic acid occurring in many plants and vegetables. It is produced in the body by metabolism of glyoxylic acid or ascorbic acid. It is not metabolized but excreted in the urine. It is used as an analytical reagent and general reducing agent.

Oxalic Acid Formula

Oxalic Acid Formula

Oxalic acid is an organic compound found in many plants.

These include leafy greens, vegetables, fruits, cocoa, nuts and seeds (1Trusted Source).

In plants, it’s usually bound to minerals, forming oxalate. The terms “oxalic acid” and “oxalate” are used interchangeably in nutrition science.

Your body can produce oxalate on its own or obtain it from food. Vitamin C can also be converted into oxalate when it’s metabolized.

C2O4H2 ⇌ C2O4H + H+    
C2O4H ⇌ C2O2−4 + H+

Once consumed, oxalate can bind to minerals to form compounds, including calcium oxalate and iron oxalate. This mostly occurs in the colon, but can also take place in the kidneys and other parts of the urinary tract.

For most people, these compounds are then eliminated in the stool or urine.

However, for sensitive individuals, high-oxalate diets have been linked to an increased risk of kidney stones and other health problems.

Oxalic Acid Vaporizer

Was this all because of the large crystalline deposits of calcium oxalate that had formed in Napoléon’s kidneys? Probably not: it seems the war was lost as soon as it was declared because of Prussian technical and organizational superiority.

However, the Emperor was not very keen to take up arms in the first place, with some of his advisors the chief warmongers. How well he was able to resist and counteract them while being beset by the very painful condition known as kidney stones are difficult to know.

It is easier to turn to the kidney stones themselves because these are susceptible to detailed methods of scientific interrogation such as X-ray diffraction. They are formed by two simple components, positive calcium ions, Ca2+, and negative oxalate ions, giving a compound conveniently enough known simply as calcium oxalate.

Oxalic acid is the theme of this podcast and the oxalate anions are what you get, together with Hions, when you dissolve crystals of this strong acid in water.  Oxalic acid is a small molecule with the formula C2O4H2, but is perhaps better represented as HOOC-single-bond-COOH: just two carboxylic acid groups joined together to make it the simplest organic di-acid. You may know this chemical as the compound that makes rhubarb have that special acidic tang to the taste, but it is also found in spinach and a number of other veggies that most of us happily eat. It is also part of our normal metabolism and occurs completely naturally in our bodies.

Oxalic Acid Dihydrate

Succinic acid, also called Butanedioic Acid, a dicarboxylic acid of molecular formula C4H6O4 that is widely distributed in almost all plant and animal tissues and that plays a significant role in intermediary metabolism. It is a colorless crystalline solid, soluble in water, with a melting point of 185–187° C (365–369° F).

Succinic acid was first obtained as a distillation product of amber (Latin: succinum), for which it is named. The common method of synthesis of succinic acid is the catalytic hydrogenation of maleic acid or its anhydride, although other methods are being used and investigated. Succinic acid has uses in certain drug compounds, in agricultural and food production, and in manufacturing.

Normally, calcium and small amounts of oxalate are present in the urinary tract at the same time, but they remain dissolved and cause no problems.

However, sometimes they bind to form crystals. In some people, these crystals can lead to the formation of stones, especially when oxalate is high and urine volume is low.

Small stones often don’t cause any problems, but large stones can cause severe pain, nausea, and blood in the urine as they move through the urinary tract.

Although there are other types of kidney stones, about 80% are made up of calcium oxalate.

For this reason, people who have had one episode of kidney stones may be advised to minimize their consumption of foods high in oxalate.

However, across-the-board oxalate restriction is no longer recommended to every person with kidney stones. This is because most of the oxalate found in urine is produced by the body, rather than absorbed from food.

Most urologists now only prescribe a strict low-oxalate diet (less than 50 milligrams per day) for patients who have high levels of oxalate in their urine.

Therefore, it’s important to be tested from time to time to figure out how much restriction is necessary.

What is oxalic acid used for?

Oxalic acid is widely used as an acid rinse in laundries, where it is effective in removing rust and ink stains because it converts most insoluble iron compounds into a soluble complex ion.

Is oxalic acid harmful to humans?

Oxalic acid is toxic because of its acidic and chelating properties. It may cause burns, nausea, severe gastroenteritis and vomiting, shock and convulsions. It is especially toxic when ingested. As little as 5 to 15 grams (71 mg/kg) may be fatal to humans.

What foods contain oxalic acid?

These include leafy greens, vegetables, fruits, cocoa, nuts and seeds ( 1 ). In plants, it’s usually bound to minerals, forming oxalate. The terms “oxalic acid” and “oxalate” are used interchangeably in nutrition science. Your body can produce oxalate on its own or obtain it from food.