|  | Diet Nutrition | Nutrition

Alkaline Characteristics

An alkaline substance can most broadly be defined as having a pH of above 7. The term alkaline is used almost interchangeably with basic, yet not all basic substances are alkali. Generally, the same chemical principles that allow an individual to identify bases (as opposed to acids) can be applied to alkaline substances, such as its chemical makeup, its reaction with acids, its texture, its bitter taste and its reaction to litmus paper.

  1. Chemical Properties

    • All basic substances have a pH of above 7. When dissolved in water, all bases will accept hydronium ions or donate hydroxide ions, either of which will lower the acidity and raise the pH. Almost all basic and alkaline substances will contain hydroxy groups (OH). For instance, sodium hydroxide (NaOH) can be identified as basic due to its hydroxy group (OH). Alkaline substances also will saponify lipids (turn into soap when in contact with fat or grease) and, for this reason, are commonly used as household cleaners.

    Distinction from Bases

    • Alkaline and basic substances overlap in most of their chemical properties. Nevertheless, while all alkali substances are basic, not all bases are alkali. To be properly labeled alkaline, a base must be water soluble (will dissolve in water) and donate hydroxide ions.

    Observable Properties

    • Without a knowledge of the chemical makeup of a certain substance, it is possible to deduce whether the substance is acidic or basic. The most precise method of doing so would be to apply the substance in question to litmus paper. Alkaline chemicals will turn red litmus paper blue. Alkaline substances will furthermore have a soapy texture (due to the saponification reaction with the oil on human skin) and a bitter taste.

    Neutralization Reaction with Acids

    • Acids and bases are seen as chemically opposite, as acids increase the hydronium ion concentration within water while bases will reduce it. When acids and bases come in contact, the result is a neutralization reaction. For instance, when sodium carbonate (NaOH) and hydrochloric acid (HCl) are combined, they will precisely neutralize, leaving only NaCl or table salt as a biproduct. An acid combined with a strong base, however, will cause a violent exothermic reaction.

Nutrition - Related Articles