Similarly, the muscles that maintain our posture contract and relax in a synchronized fashion. If the spasm is forceful and sustained, it becomes a cramp. A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax. Muscle cramps cause a visible or palpable hardening of the involved muscle. Muscle cramps can last anywhere from a few seconds to a quarter of an hour or occasionally longer.
CH3COOH is the chemical formula for acetic acid (vinegar). It is also called ethanoic acid. It is considered to be a weak acid as it is only a partially dissociated acid in water.
Carbonic acid. Carbonic acid is a chemical compound with the chemical formula H2CO3 (equivalently OC(OH)2). It is also a name sometimes given to solutions of carbon dioxide in water (carbonated water), because such solutions contain small amounts of H2CO3. In physiology, carbonic acid is described as volatile acid or respiratory acid, because it is the only acid excreted as a gas by the lungs.