What is the correct order for solubility in water among NaClO4, KClO4, NaBF4, and NaF?

The assertion that all the given compounds are soluble in water is accurate based on the general solubility rules for ionic compounds. Sodium chloride perchlorate (NaClO4), potassium chloride perchlorate (KClO4), sodium tetrafluoroborate (NaBF4), and sodium fluoride (NaF) all dissociate into their respective ions when dissolved in water, which confirms their solubility.

Typically, compounds containing alkali metal cations—such as sodium (Na) and potassium (K)—as well as anions like perchlorate (ClO4^-) and tetrafluoroborate (BF4^-) are highly soluble due to the strong electrostatic interactions between the ions and the polar water molecules.

Sodium fluoride, while slightly less soluble compared to the perchlorate salts, still qualifies as soluble owing to the overall rule that most alkali metal salts are soluble in water. Therefore, the statement that all of these compounds are soluble holds true and provides a comprehensive understanding of their behavior in aqueous solutions.