Citric acid is an organic acid. It can be found among other places in citrus fruits such as lemons and limes. It is a weak acid which means it only partially dissociates in water and it shares similar properties with other carboxylic acids.
Citric acid has a chemical formula of C6H8O7 / HOC(CH2COOH)2COOH 
IUPAC name: 2-hydroxypropane-1,2,3-tricarboxylic acid
Melting Point: 153 °C
Boiling Point: decomposes