Defining a Chemical Base
In chemistry, a base is a substance that, when dissolved in water, can accept protons (H+ ions) or donate a pair of valence electrons, depending on the definition (Arrhenius, Brønsted-Lowry, or Lewis). Bases typically have a bitter taste, feel slippery, and react with acids to form a salt and water.
Key Properties and Types of Bases
Bases are characterized by their ability to increase the hydroxide ion (OH-) concentration in an aqueous solution (Arrhenius and Brønsted-Lowry definitions). Strong bases dissociate completely in water, producing many OH- ions, while weak bases only partially dissociate. Common types include hydroxides of alkali and alkaline earth metals (e.g., NaOH, Ca(OH)2) and organic compounds like amines.
Bases in Everyday Life and Reactions
A common example of a strong base is sodium hydroxide (NaOH), often found in drain cleaners. Ammonia (NH3), a weak base, is a component of many household cleaning products and window cleaners. When a base reacts with an acid, it undergoes a neutralization reaction. For instance, NaOH (a base) reacts with HCl (an acid) to produce NaCl (a salt) and H2O (water).
Importance and the pH Scale
Bases play crucial roles in various industrial processes, biological systems (like blood pH regulation), and everyday applications, from antacids to soap production. The strength of a base is measured on the pH scale; solutions with a pH greater than 7 are considered basic or alkaline, with higher numbers indicating stronger basicity, reaching up to 14.