lab report of maleic acid into fumaric acid

1. Assuming that equilibrium concentration was achieved in procedure A, which isomer would you classify as the more stable with respect to transformation of one into the other?
2. What do each of the following tests contribute to your knowledge of the structure of each isomer?
(a) The reaction with magnesium and sodium carbonate.
(b) The pH value.
(c) The melting point.
3. Considering the structures of the two isomers, try to account for the observed differences in solubility and melting point.
4. One of the isomers can lose a molecule of water from each molecule of acid when its two carboxyl groups react to form an anhydride. Which structural isomer, cis or trans, do you predict it is?