Citric Acid is a naturally occurring weak organic acid commonly found in lemons, oranges, limes and other citrus fruit. Citric acid is also produced as a by product of the citric acid cycle during metabolism in living organisms. Its also a natural preservative and added to food producing an acidic or sour taste.

At room temperature citric acid appears as a white or clear crystalline solid. It melts at 156oC and boils as 310oC. Citric Acid will dissolve in water; this process is endothermic and reduces the latent temperature of the water as the entropy increases. The molecular formula for Citric Acid (anhydrous) is C6H8O7.