Your stomach acid is strong enough to dissolve metal
Human stomach juice consists mostly of hydrochloric acid, maintaining a highly acidic pH between 1.5 and 2.0. Laboratory studies demonstrate that human gastric fluid can dissolve pure zinc and significantly corrode steel razor blades over twenty-four hours. A thick layer of protective mucus continuously prevents your stomach from digesting itself.
The Chemistry of Gastric Fluid
Gastric juice is a specialized digestive fluid produced in the stomach, composed primarily of hydrochloric acid, potassium chloride, and sodium chloride. In a healthy human stomach, the concentration of hydrochloric acid is sufficient to keep the resting pH of gastric fluid between 1.5 and 2.0, though it can fluctuate between 1.0 and 3.5 depending on digestive activity. Because the pH scale is logarithmic, a solution at pH 2 has ten times the concentration of hydrogen ions as a solution at pH 3, and a hundred thousand times that of pure water at pH 7.
Hydrochloric acid is a strong mineral acid that fully dissociates in aqueous solution into hydronium ions and chloride ions. This high concentration of free hydronium ions gives gastric juice remarkable chemical potency. In laboratory experiments, gastric acid readily reacts with base metals such as zinc and unpassivated steel. The acid oxidizes the metal, releasing elemental hydrogen gas and dissolving the metal atoms into aqueous metal chlorides. While highly corrosion-resistant alloys can withstand the fluid for longer periods, softer metals and standard carbon steels degrade quickly when submerged in human gastric secretions.
How Parietal Cells Generate Strong Acid
The production of gastric acid takes place inside specialized epithelial cells known as parietal cells, or oxyntic cells, located within the gastric glands of the stomach lining. Creating an environment with a million-fold higher concentration of hydrogen ions than the surrounding blood requires a massive expenditure of cellular energy. Parietal cells achieve this through an enzyme called hydrogen potassium adenosine triphosphatase, commonly known as the gastric proton pump.