Questions: For oxyacids of the same general structure but differing electronegativities of the central atoms, acid strength decreases with increasing electronegativity of the central atom. The strongest acid known is HF because Acid strength in a series of fluorine is the most H-A molecules increases electronegative element. with increasing size of A.

Solution Steps

The first statement is: "For oxyacids of the same general structure but differing electronegativities of the central atoms, acid strength decreases with increasing electronegativity of the central atom."

For oxyacids, the acid strength generally increases with the electronegativity of the central atom. This is because a more electronegative central atom can better stabilize the negative charge on the conjugate base after the acid donates a proton. Therefore, the statement is false.

The second statement is: "The strongest acid known is HF because."

Hydrofluoric acid (HF) is not the strongest acid known. In fact, HF is a weak acid compared to other hydrogen halides like HCl, HBr, and HI. The strongest acids are typically superacids, such as fluoroantimonic acid. Therefore, the statement is false.

The third statement is: "Acid strength in a series of $\mathrm{H}-\mathrm{A}$ molecules increases with increasing size of A."

In a series of hydrogen halides (e.g., HF, HCl, HBr, HI), the acid strength increases with the size of the halogen atom (A). This is because larger atoms have longer and weaker H-A bonds, making it easier for the molecule to donate a proton. Therefore, the statement is true.

Final Answer