What is Acid?
Acid, any substance that in water solution tastes bitter, adjustments the color of sure indicators (e.g., reddens blue litmus paper), reacts with some metals (e.g., iron) to liberate hydrogen, reacts with bases to type salts, and promotes sure chemical reactions (acid catalysis). Examples of acids embody the inorganic substances referred tas the mineral acids sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acids—and the natural compounds belonging to the carboxylic acid, sulfonic acid, and phenol teams. Such substances include a number of hydrogen atoms that, in resolution, are launched as positively charged hydrogen ions.
Broader definitions of an acid, to incorporate substances that exhibit typical acidic behavior as pure compounds or when dissolved in solvents apart from water, are given by the Brønsted–Lowry theory and the Lewis theory. Examples of nonaqueous acids are sulfur trioxide, aluminum chloride, and boron trifluoride.