The chemical formula for calcium hydrogen tartrate is Ca(HC₄H₄O₆)₂. This compound is also commonly known as calcium bitartrate.
Understanding Calcium Hydrogen Tartrate
Calcium hydrogen tartrate is a salt formed from calcium ions (Ca²⁺) and hydrogen tartrate ions (HC₄H₄O₆⁻). It is derived from tartaric acid (H₂C₄H₄O₆), a dicarboxylic acid naturally found in many plants, particularly grapes. When tartaric acid loses one proton, it forms the hydrogen tartrate (or bitartrate) ion.
- Calcium Ion: Ca²⁺
- Hydrogen Tartrate Ion: HC₄H₄O₆⁻
For electrical neutrality, one calcium ion (with a +2 charge) combines with two hydrogen tartrate ions (each with a -1 charge), resulting in the formula Ca(HC₄H₄O₆)₂.
Distinction from Calcium Tartrate
It's important to differentiate calcium hydrogen tartrate from calcium tartrate, which is a distinct chemical compound. The provided information about calcium tartrate highlights these differences:
- Calcium Tartrate: In this compound, calcium combines with the fully deprotonated tartrate ion (C₄H₄O₆²⁻). Therefore, the chemical formula for calcium tartrate is CaC₄H₄O₆.
- Key Difference: The presence of hydrogen within the tartrate part of "calcium hydrogen tartrate" signifies that the tartaric acid has only lost one of its two acidic protons, forming the bitartrate ion. In contrast, "calcium tartrate" means both acidic protons have been lost from the tartaric acid molecule.
Here's a comparison of the two related calcium salts of tartaric acid:
| Feature | Calcium Hydrogen Tartrate (Calcium Bitartrate) | Calcium Tartrate |
|---|---|---|
| Chemical Formula | Ca(HC₄H₄O₆)₂ | CaC₄H₄O₆ |
| Anion | Hydrogen Tartrate (HC₄H₄O₆⁻) | Tartrate (C₄H₄O₆²⁻) |
| Source (Tartaric Acid) | One proton lost | Both protons lost |
| Molar Mass (Anhydrous) | Approx. 338.22 g/mol | Approx. 190.16 g/mol |
| Common Use | Stabilizer, pH regulator | Food additive, chelating agent |
(Note: Molar mass for Calcium Tartrate provided is for anhydrous form.)
Applications and Characteristics
Calcium hydrogen tartrate, like other tartrates, plays roles in various industries. It can act as a leavening agent in baking and as a pH regulator. Calcium tartrate itself, as noted, typically appears as a hygroscopic white powder or colorless crystals and has applications as a food additive and chelating agent.
Understanding the subtle but significant difference in chemical structure, particularly the presence or absence of hydrogen in the tartrate moiety, is crucial for correctly identifying and utilizing these compounds. For further details on tartaric acid and its derivatives, you can refer to general chemical resources such as Wikipedia's page on Tartaric Acid.
