An acid is a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals (like calcium) to form salts. Acids are used as additives to drinks and foods, as they alter their taste and serve as preservatives. Phosphoric acid is a component of cola drinks. Acetic acid is nothing but vinegar. Carbonic acid is an important part of some cola drinks and soda. Citric acid is used as a preservative in sauces and pickles. Tartaric acid is an important component of some commonly used foods like unripened mangoes and tamarind. Citric acid is present in oranges, lemon and other citrus fruits. Oxalic acid is present in tomatoes, spinach, and especially in carambola and rhubarb (rheum); rhubarb leaves and unripe carambolas are toxic because of high concentrations of oxalic acid.

acet-ac, benz-ac, but-ac, carb-ac, chrom-ac, cit-ac, fl-ac, gall-ac, hipp-ac, hydr-ac, mur-ac, nit-ac, ox-ac, ph-ac, pic-ac, succ-ac, sul-ac, tart-ac