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Which common substances are bases according to the Arrhenius theory?
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Log burning in a fire. Burning wood is an example of a chemical reaction in which wood in the presence of heat and oxygen is transformed into carbon dioxide, water vapor, and ash.
According to the Arrhenius theory, a base is a substance that increases the concentration of hydroxide ions (OH⁻) when dissolved in an aqueous solution.12
Common substances classified as bases under this theory include:
- Metal Hydroxides: These are among the most well-known bases. Examples include sodium hydroxide (NaOH), often called caustic soda or lye, and calcium hydroxide (Ca(OH)₂), known as slaked lime. Other alkali and alkaline earth metal hydroxides, such as those of potassium, lithium, barium, and strontium, also function as bases.1324
- Ammonia and Derivatives: Ammonia (NH₃) acts as a base because it reacts with water to produce hydroxide ions. Similarly, organic derivatives of ammonia, known as amines, function as bases.24
- Natural and Synthetic Compounds: Many complex organic molecules, including nicotine, caffeine, morphine, and cocaine, act as bases because they contain a nitrogen atom that allows them to react with water to yield hydroxide ions.2