Final answer:
Between phenoxide and methoxide, methoxide is the stronger base due to its localized negative charge making it more reactive and ready to accept a proton, whereas the negative charge on phenoxide is delocalized through resonance, stabilizing it and making it less reactive. option b is correct
Step-by-step explanation:
option b is correct The question pertains to the comparison of the basicity of two different bases: phenoxide and methoxide. To determine which of the two is the stronger base, we must consider the ability of each ion to donate an electron pair or abstract a proton in aqueous solution. In general, the strength of a base is dictated by its tendency to ionize completely in solution. However, both phenoxide and methoxide are not strong bases in the sense that they do not contain OH as part of their formula and hence are not 100% ionized in solution.
Nonetheless, between the two, methoxide (CH3O-) is the stronger base compared to phenoxide (C6H5O-). This is because methoxide is less stabilized than phenoxide. The negative charge on methoxide is localized on the oxygen atom, making it more reactive and ready to accept a proton. In contrast, phenoxide has the negative charge distributed over the aromatic ring through resonance, which stabilizes the negative charge and makes it less available for protonation. Therefore, the correct answer is methoxide
In general, a stronger base is one that is more likely to donate a hydroxide ion (OH-) in solution. Among the options given, phenoxide and methoxide, both are strong bases because they are negatively charged and contain an oxygen atom bonded to an alkyl group. However, the strength of a base can also depend on the stability of its conjugate acid. In this case, the conjugate acid of phenoxide (phenol) is more stable than the conjugate acid of methoxide (methanol), which makes phenoxide a stronger base than methoxide.