Final answer:
The correct answer is option B. The strongest base among phenoxide, methoxide, bromide, and ketone is methoxide, given its greater ability to donate electrons compared to the others.
Step-by-step explanation:
The question provided is related to the strength of bases and acids. Specifically, it asks which of the given species is the strongest base: phenoxide, methoxide, bromide, or ketone. To determine the strongest base among these, we need to look at their ability to donate an electron pair or accept a proton in a chemical reaction according to the Brønsted-Lowry definition of a base.
Among the options, methoxide (B) is the strongest base. This is because methoxide ion, (CH3O-), is the conjugate base of methanol, and it is known for its high reactivity and strong ability to donate electrons. Phenoxide is also a strong base, but it is stabilized by resonance, which can reduce its basicity in comparison to methoxide. Bromide (Br-) is a weak base as halides are not particularly basic. Ketones are neutral compounds and do not readily act as bases, especially in the presence of the other given options.
To further clarify the concept of base strength, consider the example comparing CH3NH2 (methylamine) and (CH3)2NH (dimethylamine). In this case, dimethylamine is the stronger base due to its lower steric hindrance and higher electron donating ability. This is supported by a larger equilibrium constant (Kb) for the base reaction, indicating stronger base strength.