Which of the following best explains why sulfuric acid,
CHEMISTRY · Single correct · AP · Chemistry · Acids and Bases · Acids and Bases
Problem
Which of the following best explains why sulfuric acid, H2SO4, is much stronger than selenic acid, H2SeO4?
(a) Sulfur–oxygen bonds are longer than selenium–oxygen bonds, which weakens the O–H bond and makes sulfuric acid stronger.
(b) Sulfuric acid has more oxygen atoms attached to the central atom than selenic acid, providing greater resonance stabilization of the conjugate base.
(c) Sulfur is more electronegative than selenium, withdrawing electron density from the O–H bond and stabilizing the conjugate base.
(d) Sulfur cannot expand its valence shell as much as selenium, leaving more formal negative charge on oxygen and thereby strengthening the acid.