'Ka ' for an acid is higher, the stronger is the acid; relate the strength of an acid with 'pKa ' :
Correct answer: D. Both "Higher pKa , weaker the acid" & "Lower pKa , stronger the acid"
- A. Higher pKa , weaker the acid
- B. Lower pKa , stronger the acid
- C. pKa has no relation with acid strength
- D. Both "Higher pKa , weaker the acid" & "Lower pKa , stronger the acid"
Explanation
The acid dissociation constant Ka measures acid strength; higher Ka means a stronger acid. pKa is related to Ka by the formula pKa = −log Ka , so a lower pKa corresponds to a higher Ka. Thus, lower pKa → stronger acid, higher pKa → weaker acid.
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About Acids, Bases and Salts
Acid and base behaviour is explained through the Bronsted-Lowry transfer of protons and the Lewis donation or acceptance of electron pairs. The topic includes pH, pOH, ionisation and water equilibrium, plus salt formation and hydrolysis, where a salt solution may become acidic, basic or neutral.
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