Question

Which is the stronger acid, HClO₄ or HBrO₄? Why?

a. HClO₄:
HClO₄ is stronger due to higher electronegativity of Cl.
b. HBrO₄:
HBrO₄ is stronger due to the larger size of Br.
c. HClO₄:
HClO₄ is stronger due to the larger size of Cl.
d. HBrO₄:
HBrO₄ is stronger due to higher electronegativity of Br.

Answer 1

HClO₄ is the stronger acid compared to HBrO₄ because the higher electronegativity of Cl compared to Br leads to a weaker O-H bond in the oxyacid, facilitating the release of H+.

Step-by-step explanation:

The stronger acid between HClO₄ (perchloric acid) and HBrO₄ (perbromic acid) can be determined by examining the electronegativity of the central atoms.

Acid strength in oxyacids increases with the electronegativity of the central atom because a more electronegative atom will exert a stronger pull on the electron pairs in the O-H bond, thereby weakening the bond and making it easier to release the hydrogen ion (H+). Since chlorine (Cl) is more electronegative than bromine (Br), HClO₄ is the stronger acid.