explain the isomerism exhibited by melic and funmeric acids
The geometrical isomerism of ethylene compounds has been studied in great detail using the example of maleic and fumaric acids. Both acids are colorless crystals. Maleic acid, the cis isomer (I), has a melting point of 130°C and a boiling point of 160°C; fumaric acid, the trans isomer (II), has a melting point of 286°C and a boiling point of 290°Maleic acid dissolves readily in water and ether; fumaric acid is practically insoluble in water and nearly all organic solvents. Maleic acid is stronger than fumaric acid but less stable. It is readily converted to fumaric acid under exposure to light or upon heating to temperatures above 200°C. Fumaric acid is converted to maleic acid upon exposure to ultraviolet irradiation.