emäset

Emäset, or bases, are a class of chemical species characterized by their ability to raise the pH of solutions or to neutralize acids. In chemistry, several theories describe what makes a substance a base. Arrhenius bases release hydroxide ions (OH−) in water; Bronsted–Lowry bases accept protons (H+); Lewis bases donate electron pairs. These definitions overlap but emphasize different aspects of basicity.

Common examples include strong bases such as sodium hydroxide (NaOH) and potassium hydroxide (KOH), which dissociate completely in water, and weak bases such as ammonia (NH3) and bicarbonate (HCO3−), which accept protons to a lesser extent. The strength of a base depends on its tendency to produce hydroxide or to accept protons in a given context.

Properties of bases vary: many bases raise pH and feel slippery; strong bases are caustic and reactive, especially with acids and oxidizing agents. In aqueous solution bases neutralize acids to form a salt and water (a neutralization reaction). They may also act as Lewis bases, donating electron pairs to electron-deficient species.

Uses and occurrence: bases are ubiquitous in chemistry and biology. They are used in industry for cleaning and processing, in paper and soap production, and in various chemical syntheses. In biology, buffering systems such as bicarbonate and phosphate help maintain pH in blood and cells. Safety considerations include chemical burns and irritation; appropriate storage and handling are essential.