In: Chemistry
Though they are not necessary in every situation, solvents are used when performing reactions for many reasons. What function does a solvent serve in a reaction (list two)? What characteristics are important to consider when selecting a solvent (list two)? This is regards to organic chemistry, please explain your answers, please!
Solvent is something that serves as a medium for a reaction. It is generally written along with the reagent on the reaction arrow and that may cause confusion at times. In regards to organic chemistry, functions of solvent are:
1) It is used to dissolve the reactants. We choose polar solvents for polar reactants and non-polar solvents for non polar reactants. In this case, the solvent does not directly participate in the reaction but only provides a medium for dissolving the reactants.
2) It can directly participate in the reaction by acting as a source of proton (acid) or lone pair (nucleophile) for the corresponding substrate. Here, solvent directly participates in the reaction.
Important things to keep in mind when selecting a solvent for an organic reaction is:
1) Is the solvent protic or aprotic: We need to consider whether the solvent is a source of protons or not because all unimolecular reactions(SN1/E1) need protic solvent for reaction to proceed as carbocation formed in rate determining step is stabilized in such a protic solvent. On the other hand, SN2/E2 is done in polar aprotic solvent.
2) Boiling temperature: Solvent selected should typically have a low boiling temperature so that it can easily be removed from the product after reaction completion.