Foundation
Chemistry Foundation
Theories of Acids and Bases
Question
The strongest acid of the following is -
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Solution
Acid strength depends on the stability of its conjugate base. More stable conjugate base means stronger acid. For oxyacids, strength increases with the number of oxygen atoms attached to the central atom and with the electronegativity of that atom.
Comparing the options:
- HClO4 (Perchloric acid) has the highest number of oxygen atoms (4) and a very electronegative chlorine atom. Its conjugate base, ClO4-, is highly stable due to resonance and equal distribution of the negative charge.
- H2SO4 and HCl are strong but weaker than HClO4.
- H3PO4 is a weak acid.
Therefore, HClO4 is the strongest acid among the given options.
Final Answer: HClO4