Chemistry - CHEMICAL BONDING Question with Solution | TestHub
A student measures the acidic strength of HX in different solvents and obtains the following observations:
In water: HI > HBr > HCl > HF
In DMSO (aprotic, non-hydrogen-bonding solvent): HF > HCl > HBr > HI
Which explanation best accounts for this change in order?
Options:
Answer:
Solution:
Concept:
• Acid strength in different solvents
• Solvation effects
• Bond dissociation energy dominance in aprotic solvents
Solution:
• In water, strong solvation of small anions (F⁻) reduces HF acidity → trend: HI > HBr > HCl > HF.
• DMSO is aprotic → poor solvation → acid strength depends mainly on H–X bond dissociation energy.
• H–F bond strongest → HF becomes a stronger acid in DMSO relative to HI.
• Therefore, both solvent effects (A) and bond energy (B) are relevant.
Final Answer: Option (d)