Water hardness refers to the presence of specific dissolved minerals. The primary examples of what makes water hard are the specific types of positively-charged ions it contains.
Understanding Water Hardness
According to the provided reference, water is considered hard when it contains a large amount of certain positively-charged ions, known as cations. These ions are typically picked up by water as it passes through underground minerals.
Key Examples of What Makes Water Hard
Based on the reference, the specific examples of ions that contribute to water hardness include:
- Calcium ions (Ca²⁺): Often dissolved into water as it flows through mineral deposits like limestone.
- Magnesium ions (Mg²⁺): Another common ion found in hard water, often originating from similar mineral sources as calcium.
- Ferric ions (Fe³⁺): While less common than calcium and magnesium, the presence of ferric ions can also contribute to water hardness, particularly in areas with iron-rich minerals.
These ions are introduced into the water supply when water interacts with mineral deposits. A notable example of a mineral that sources calcium, contributing significantly to hardness, is limestone.
Sources of Hardness
The hardness-causing ions primarily come from natural minerals. When water moves through soil and rock formations, it dissolves these minerals, picking up the ions.
Here's a simple breakdown of the key components and sources mentioned:
| Hardness-Causing Ion | Common Mineral Source Example |
|---|---|
| Calcium (Ca²⁺) | Limestone |
| Magnesium (Mg²⁺) | Often found with calcium |
| Iron (Fe³⁺) | Iron-containing minerals |
Note: The reference specifically names limestone as a source of calcium.
In summary, the examples of the components that constitute water hardness are the specific cations—Calcium (Ca²⁺), Magnesium (Mg²⁺), and Ferric (Fe³⁺)—which are dissolved into the water, often from minerals like limestone.
