No, elementary calcium itself reacts with water rather than simply dissolving, but many calcium compounds are water soluble to varying degrees. Understanding the distinction between the element and its compounds is key to answering this question accurately.
Elemental Calcium and Its Reaction with Water
When we talk about elementary calcium (the pure metallic element, Ca), it does not simply dissolve in water to form a solution. Instead, it undergoes a chemical reaction. This reaction produces calcium hydroxide and hydrogen gas, often observed as bubbling. Therefore, elemental calcium is not considered water soluble in the traditional sense of forming a stable, homogenous solution.
Calcium Compounds and Their Varied Solubility
In contrast to the elemental form, calcium compounds are more or less water soluble. This means that while some calcium compounds dissolve readily in water, others have very limited solubility, often considered insoluble for practical purposes, though they do dissolve to a small extent. The solubility of these compounds is crucial in various natural processes and industrial applications, from water hardness to bone formation.
Here are examples of the solubility of some common calcium compounds, as per the provided reference:
| Calcium Compound | Solubility in Water (at standard conditions) | Notes |
|---|---|---|
| Calcium Carbonate | 14 mg/L | Increases by a factor of five in the presence of carbon dioxide. |
| Calcium Phosphate | 20 mg/L | |
| Calcium Fluoride | 16 mg/L |
As seen from the table, compounds like calcium carbonate, calcium phosphate, and calcium fluoride have relatively low solubilities (measured in milligrams per liter). This low solubility is why calcium carbonate is a major component of limestone and shells, and why calcium phosphate is a primary component of bones and teeth – they are stable and do not easily dissolve away in water.
In summary, while elementary calcium chemically reacts with water, its diverse array of compounds exhibit a spectrum of water solubility, from very low to significantly higher, playing vital roles across various systems.
