NS meaning in Chemistry ?

Saline (also known as saline solution) is a mixture of sodium chloride (salt) and water and has a number of uses in medicine. Applied to the affected area it is used to clean wounds, help remove contact lenses, and help with dry eyes. By injection into a vein it is used to treat dehydration such as from gastroenteritis and diabetic ketoacidosis.

Large amounts may result in fluid overload, swelling, acidosis, and high blood sodium. In those with long-standing low blood sodium, excessive use may result in osmotic demyelination syndrome. Saline is in the crystalloid family of medications. It is most commonly used as a sterile 9 g of salt per litre (0.9%) solution, known as normal saline. Higher and lower concentrations may also occasionally be used. Saline is acidic, with a pH of 5.5 (due mainly to dissolved carbon dioxide).

The medical use of saline began around 1831. It is on the World Health Organization's List of Essential Medicines. In 2017, sodium was the 225th most commonly prescribed medication in the United States, with more than two million prescriptions.