Question

1. Consider the reaction below for a solution in which the two molecules are both present at 1 mM: R1. R3 R1 R3 C=O ... H-N = C=O + H-N R4 R2 R4 Discuss the equilibrium of the reaction when the solvent is water versus hexane. Solvent molecules are not shown (but need to be considered). Make sure to include your reasoning.

Answer 1

The explanation to the given question is as follows: as the water is polar solvent with 1.84 D as its dipole moment and is the second highest known dipole moment, water is quite good in stablesing the polar species and is used in reaction where polar interactions are required to occur, as in the given case where we can see that there is H-bonding between the two molecules (shown as dotted lines, left picture) which is possible and stable only when there is polarity of carbony and amine both, these molecules have higher polarity when water is used as solvent and so the equilibrium shifts backward, on the other hand hexane is a non polar solvent in the the two will not dissolved and also the polarity of the reactants will be reduced due to which the equilibrium will be shifted forward.