Which of the following is NOT considered a common base?

The answer is correct because chlorides, which are compounds containing the chloride ion (Cl⁻), do not generally exhibit basic properties. In contrast, hydroxides (like sodium hydroxide) and carbonates (like sodium carbonate) are well-known bases. Hydroxides are considered strong bases that can readily dissociate in water to produce hydroxide ions (OH⁻), while carbonates can react with acids to produce carbon dioxide and a salt while also affecting the pH of a solution, exhibiting basic behavior.

The role of bases is critical in various chemical reactions, particularly in neutralization reactions with acids, and this distinction highlights why chlorides do not fit into the category of common bases. Thus, while hydroxides and carbonates are recognized for their basic characteristics, chlorides lack this functionality and are commonly neutral or even acidic in nature.