Final answer:
To select a developing solvent when none is specified, consider the polarity and reactivity of the reactants. Use polar solvents, such as polar protic or polar aprotic solvents, for polar substrates and ionic nucleophiles, ensuring the solvent does not interfere with the reaction.
Step-by-step explanation:
When choosing a developing solvent for a reaction where none is specified, one must consider the polarity and type of the compounds involved. Since the substrate mentioned is a polar compound like CH2-Br and the nucleophile is an ionic compound such as Na+ OH- or CH2O-Na+, a polar solvent is required to effectively dissolve both components.
Polar solvents are categorized into two main types: polar protic solvents and polar aprotic solvents. Polar protic solvents, like water (H2O) or methanol (CH3OH), can establish hydrogen bonds and are suitable for reactions involving neutral nucleophiles like water or alcohol. These solvents often define SN1 and E1 reaction conditions.
In contrast, polar aprotic solvents, which don't have hydrogen atoms bonded to electronegative atoms, might also be considered depending on the specific reactivity and solubility needs. The chosen solvent must not only dissolve the reactants but also should not participate in the reaction or cause side reactions.
To concentrate solutions that include solvents, methods such as boiling or evaporating are used, which is guided by the dilution equation assuming the solute remains stable upon heating. Solvents with lower boiling points can be easier to remove if concentrating the solute is necessary post-reaction.