Alkaline

Alkaline

Alkaline substances are those that have a pH greater than 7. They are the chemical opposite of acids, which have a pH less than 7. Alkaline substances are also known as bases. The concept of alkalinity is important in various fields, including chemistry, biology, medicine, and environmental science.

Properties of Alkaline Substances

Alkaline substances have several characteristic properties:

• Taste: Alkaline substances often have a bitter taste.
• Feel: They can feel slippery or soapy to the touch.
• Reactivity: Alkaline substances can react with acids in a neutralization reaction to form water and a salt.
• Electrical Conductivity: In aqueous solution, alkaline substances can conduct electricity due to the presence of ions.

Common Alkaline Substances

Some common alkaline substances include:

• Sodium Hydroxide (NaOH): Also known as lye or caustic soda, it is used in soap making and as a drain cleaner.
• Potassium Hydroxide (KOH): Used in the manufacture of biodiesel and as an electrolyte in alkaline batteries.
• Calcium Carbonate (CaCO₃): Found in limestone and used as a dietary supplement and antacid.
• Ammonia (NH₃): Used as a cleaning agent and in the production of fertilizers.

Biological Importance

Alkalinity plays a crucial role in biological systems. The human body maintains a tightly regulated pH balance, with blood pH typically around 7.4. This slightly alkaline environment is essential for proper cellular function and enzyme activity.

Alkaline Diet

The alkaline diet is a dietary regimen that emphasizes the consumption of alkaline foods to maintain optimal health. Proponents claim that it can help prevent diseases and improve overall well-being, although scientific evidence supporting these claims is limited.

Environmental Impact

Alkalinity is an important factor in environmental science, particularly in the context of water quality. The alkalinity of water bodies affects aquatic life and the solubility of nutrients and pollutants.

Ocean Alkalinity

The ocean's alkalinity is crucial for marine life, particularly for organisms that rely on calcium carbonate for their shells and skeletons. Ocean acidification, caused by increased CO₂ levels, is a significant threat to these organisms as it reduces the ocean's alkalinity.

Measurement of Alkalinity

Alkalinity is measured using a pH scale, which ranges from 0 to 14. A pH greater than 7 indicates an alkaline solution. Alkalinity can also be measured in terms of the concentration of hydroxide ions (OH⁻) in a solution.

Applications in Medicine

In medicine, alkaline substances are used in various treatments and diagnostic procedures. For example, antacids are alkaline compounds that neutralize stomach acid to relieve symptoms of indigestion and heartburn.

See Also

• Acid
• pH
• Neutralization reaction
• Buffer solution

References

• "Chemistry: The Central Science" by Brown, LeMay, Bursten, and Murphy.
• "Principles of Biochemistry" by Lehninger, Nelson, and Cox.