Editing Acid (section)

===In food===
[[File:Tumbler of cola with ice.jpg|thumb|Carbonated water (H<sub>2</sub>CO<sub>3</sub> aqueous solution) is commonly added to soft drinks to make them effervesce.]]
[[Tartaric acid]] is an important component of some commonly used foods like unripened mangoes and tamarind. Natural fruits and vegetables also contain acids. [[Citric acid]] is present in oranges, lemon and other citrus fruits. [[Oxalic acid]] is present in tomatoes, spinach, and especially in [[carambola]] and [[rhubarb]]; rhubarb leaves and unripe carambolas are toxic because of high concentrations of oxalic acid. [[Ascorbic acid]] (Vitamin C) is an essential vitamin for the human body and is present in such foods as amla ([[Phyllanthus emblica|Indian gooseberry]]), lemon, citrus fruits, and guava.

Many acids can be found in various kinds of food as additives, as they alter their taste and serve as preservatives. [[Phosphoric acid]], for example, is a component of [[cola]] drinks. [[Acetic acid]] is used in day-to-day life as vinegar. Citric acid is used as a preservative in sauces and pickles.

[[Carbonic acid]] is one of the most common acid additives that are widely added in [[soft drink]]s. During the manufacturing process, CO<sub>2</sub> is usually pressurized to dissolve in these drinks to generate carbonic acid. Carbonic acid is very unstable and tends to decompose into water and CO<sub>2</sub> at room temperature and pressure. Therefore, when bottles or cans of these kinds of soft drinks are opened, the soft drinks fizz and effervesce as CO<sub>2</sub> bubbles come out.<ref>{{Citation|title = Method of and apparatus for making and dispensing a carbonated beverage utilizing propellant carbon dioxide gas for carbonating|url = https://patents.google.com/patent/US4304736|date = 8 December 1981|access-date = 2016-02-06|first1 = John R.|last1 = McMillin|first2 = Gene A.|last2 = Tracy|first3 = William A.|last3 = Harvill| first4 = William S. Jr. |last4 = Credle}}</ref>

Certain acids are used as drugs. [[Acetylsalicylic acid]] (Aspirin) is used as a pain killer and for bringing down fevers.