What is Benzoic acid???Where to use this??

A white crytalline compound C6H5COOH where C6H5 is a phenyl group
Relative density 1.27
melting point 122.4 degree
boiling point 249 degree
It naturally occurs in plant and is used to make food preservative
It is a weak acid with dissociation constant 6.4*10^(-5)
It has property of acids like hydrochloric acid
The benzene ring (pheynl group) undergoes substitution reaction