Dear Hosseein

Have a look at this link and attached file.

hope be useful.

http://www.whxb.pku.edu.cn/EN/abstract/abstract25728.shtml

Fumaric acid is a intermediate of the citric acid cycle , is a dicarboxylic acid commonly found in nature. Due to its acidic properties it is used in an acidulant food and beverages and as anti bacterial agent in the feed industries. Because of its double bond and two carboxylate acid groups its diffusion coefficients varies by various parameters.However for detailed study about the diffusibility of fumaric acid in water , Please refer :“Roche’s R A and others 1959.production of fumaric acid by ......Appl.,Micri biology, 7 , 74-80.”

Dear Hossein,

I think that you need to calculate diffusion coefficient of fumaric acid in water. I found some correlations. You can find these correlations at Perry's Chemical Engineers' Handbook. It should be used equation (5-214) or, even better, equation (5-215).

Symbols have the following meaning:

• Va is molar volume of component A (fumaric acid);
• µw is kinematic viscosity of water;
• T is temperature in K.

Best regards,

Obrad Milovanovic