Question

(1 point) Explain what melting point depression is and how this supposes to affect the physical state of your reaction (both reactants are solids before mixing and, upon mixing, what you expect to happen? Keep this answer in mind during your reaction and observe to see if your prediction came true)

(1.5 point) what is the structure of your expected product for all 6 possible reactions? USE CHEMDRAW

Vanillin + o-toluidine

Vanillin + m-toluidine

Vanillin + p-toluidine

o-Vanillin + o-toluidine

o-Vanillin + m-toluidine

o-Vanillin + p-toluidine

(1.5 point) For each product above, what are the expected IR bands?

(1.5 point) For each product above, what are the expected number of peaks and its integration?

Answer 1

Melting point depression is the phenomenon when a pure substance containing non-volatile impurities melt at a lower temperature or a wide range of temperatures as compared to the pure substance. When a substance melts, its solid and liquid states are in equlibrium. The presence of impurities in the solid will disrupt the lattice uniformity and less energy is required to convert it into liquid state, in short the melting temperature decreases.

When two solid reactants are mixed and the reaction is carried out, the mixture will melt at a lower tempearture as compared to both the solids taken. It may not be visible instantaneously, the mixture needs to be heated or undergoing some exothermic reaction.

The IR-bands of all the products will show a C=N stretch at 1640-1690cm^-1 along with a broad O-H band around 3300cm^-1.