Key Properties and Health Implications of Oxalate
What Does Oxalate Mean and Everything at its Base
One of the most abundant compounds that are found in the plants and the human body as well, Oxalates are a significant section under modern-day chemistry. This module revolves around educating the readers over the naturally occurring oxalate molecules, structure of oxalate ions, and all the other structures formulas that help understand the chapter at its very base. Another primary focus of the module is to educate students and readers around what is the meaning of oxalate and what it has to do with the required nutritional needs of the people. Let’s have a look at all the significant aspects of what is an oxalate.
Oxalates, What are They?
Represented by the chemical formula, C₂O₄⁻². What contains Oxalate are a dicarboxylic acid dianion composition that goes with the chemical formula of C₂O₄
Also known as Ethanedioate or Oxalate Ion or Oxalic Acid Dianion, Oxalates are one of the most abundant materials that exist on the earth’s surface, found in both plants and animals. Interestingly, the process of obtaining it through the deprotonation of the given carboxy groups of C₂H₂O₄ (oxalic acid). These specific carboxyl groups are used as a source of derivatives, similar to the likes of salts that are present over oxalic acid. Few examples over the same suggestions are dimethyl oxalate or sodium oxalate. Further, Oxalates also form superior coordination with a variety of compounds that are sometimes also abbreviated as an ‘ox’.
What Do Oxalates Do? Where are They Found and Obtained?
Oxalates are a vital nutrient to help build immunity and provide the body with proper functioning. However, too much oxalates is also not a good option as it leads to kidney stones. Therefore, it is always advisable to understand what is oxalate food and what is its constituents, to keep a check on your oxalate intake.
A form of Oxalate, Ethanedioate is one of the most abundant materials that is found over many parts of plants and can be easily obtained over the process of incomplete oxidation of carbohydrates. This way, the abundant materials can be easily led down the roots and leaves of a majority of plants, more commonly buckwheat and rhubarb; these are one of the most common examples of oxalate-rich plants. Lastly, Ethanedioate plays a significant role in acting as a plant metabolite or a human metabolite.
Properties of Oxalate - C₂O₄²
Health Hazards Related to Oxalates
Our human bodies are enriched with a number of constituents, Oxalic acid being one of the significant constituents inside. Further, the human body also comprises several forms of divalent metallic cations, similar to the forms of iron (II) and the forms of different calcium constituents that are present alongside as well. Further, these compounds can rightly be formed with crystals of the suggested corresponding oxalates. The suggested crystals can later be quickly passed through the excreted urine from our body, in the form of minute crystals.
When your body keeps dealing with high amounts of oxalates, you put yourself at a higher risk of forming kidney stones.
FAQs on Oxalate: Complete Guide for Students
1. What is the oxalate ion in chemistry?
In chemistry, the oxalate ion is a dianion with the chemical formula C₂O₄²⁻. It is also known as ethanedioate. This ion is the conjugate base of oxalic acid (H₂C₂O₄), formed when the acid loses two protons (H⁺) from its two carboxylic acid groups. It is a common component in various salts, such as sodium oxalate (Na₂C₂O₄), and acts as a ligand in coordination compounds.
2. What are the chemical formula and structure of the oxalate ion?
The chemical formula for the oxalate ion is C₂O₄²⁻. Structurally, it is a planar ion consisting of two carbon atoms joined by a single bond. Each carbon atom is also bonded to two oxygen atoms. The negative charge of -2 is delocalised across the four oxygen atoms, which can be represented by resonance structures. This delocalisation contributes to its stability.
3. What is the key difference between oxalic acid and the oxalate ion?
The primary difference lies in their protonation state and charge.
- Oxalic Acid (H₂C₂O₄): This is a neutral, weak dicarboxylic acid. It is the fully protonated form.
- Oxalate Ion (C₂O₄²⁻): This is the deprotonated form (anion) of oxalic acid, carrying a charge of -2. It is formed when oxalic acid donates both of its acidic protons.
4. Why is the oxalate ion classified as a bidentate ligand?
The oxalate ion is classified as a bidentate ligand because it can donate two electron pairs from two separate donor atoms (two of the negatively charged oxygen atoms) to a single central metal ion simultaneously. This allows it to form a stable, five-membered ring structure with the metal ion, a process known as chelation. Ligands that can form such rings are called chelating agents.
5. Explain the role of oxalate ions as a reducing agent with an example.
Oxalate ions act as a good reducing agent because the carbon atoms in the oxalate ion (with an oxidation state of +3) can be easily oxidised to carbon dioxide (CO₂), where carbon has an oxidation state of +4. A classic example is the titration of an oxalate solution with potassium permanganate (KMnO₄) in an acidic medium. In this redox reaction, the purple permanganate ion (MnO₄⁻) is reduced to the colourless Mn²⁺ ion, while the oxalate ion is oxidised to CO₂.
6. Give an example of a coordination complex featuring the oxalate ligand.
A well-known example is potassium ferrioxalate, with the formula K₃[Fe(C₂O₄)₃]. In this complex, three bidentate oxalate ions (C₂O₄²⁻) are coordinated to a central iron(III) ion (Fe³⁺). Each oxalate ligand binds to the iron ion at two positions, forming a very stable octahedral complex. In chemical notation, oxalate is often abbreviated as 'ox'.
7. How does chelation by the oxalate ligand increase the stability of a metal complex?
Chelation by the oxalate ligand significantly increases the stability of a metal complex due to the chelate effect. When a bidentate ligand like oxalate binds to a metal ion, it forms a ring structure. This process is thermodynamically more favourable (resulting in a more stable complex) than the binding of two separate monodentate ligands. The increase in stability is primarily driven by a significant positive change in entropy upon the formation of the chelate ring.
8. How can a student test for the presence of oxalate ions during salt analysis?
A standard test for the oxalate ion in qualitative analysis involves two key steps:
- Calcium Chloride Test: A neutral solution of the salt is treated with calcium chloride (CaCl₂) solution. The formation of a white precipitate of calcium oxalate (CaC₂O₄), which is insoluble in acetic acid but soluble in dilute mineral acids like HCl, indicates the presence of oxalate.
- Potassium Permanganate Test: The white precipitate is dissolved in dilute sulphuric acid. The solution is then warmed and a few drops of KMnO₄ solution are added. The pink colour of the KMnO₄ is rapidly discharged, confirming the presence of oxalate ions which reduce the MnO₄⁻.
