Benzenedicarboxylic acid
# Benzenedicarboxylic acid

Benzenedicarboxylic acid is a group of chemical compounds which are dicarboxylic derivatives of benzene. Benzenedicarboxylic acid comes in three isomers:

* Phthalic acid (1,2-benzenedicarboxylic acid)
* Isophthalic acid (1,3-benzenedicarboxylic acid)
* Terephthalic acid (1,4-benzenedicarboxylic acid)

| Common Name | Phthalic acid | Isophthalic acid | Terephthalic acid |
| - | - | - | - |
| Systematic Name | 1,2-benzenedicarboxylic acid | 1,3-benzenedicarboxylic acid | 1,4-benzenedicarboxylic acid |
| Structural Formula | | | |
| CAS Registry Number | 88-99-3 | 121-91-5 | 100-21-0 |

All isomers share the molecular weight 166.13 g/mol and the chemical formula $C_8H_6O_4.$

