Calcium Carbonate → (2E)-2-Butenedioic acid calcium salt (1:1)

Participants

Reaction Steps

A calcium fumarate sample was prepared by combining 580 g (5 moles) of fumaric acid (Pfizer, fine granular, F.C.C.) with 1650 g (92 moles) of water and 500 g (5 moles) of calcium carbonate (Baker Reagent grade) at ambient temperature. Dry calcium carbonate was added to the fumaric acid suspension in ten equal portions of 50g, one portion every 5 min. while stirring the mixture continuously using a Lightning mixer at high speed. The mole ratio of fumaric acid to CaCO3 to water was 1:1:18.4. After the final addition of calcium carbonate, the pH of the mixture was 4.95. It was found that the addition of CaCO3 to the fumaric acid proceeded through an endothermic reaction, the final temperature of the reaction vessel was 17.3° C. (63° F.) while the starting solution temperature was 19.8° C. (68° F.).

Provenance & Evidence