alleryIdentify the redox reaction:
ANaOH + HCl → NaCl + H₂O
BZn + 2 HCl → ZnCl₂ + H₂
CAgNO₃ + NaCl → AgCl + NaNO₃
DNH₃ + HCl → NH₄Cl
Answer & Solution
Correct answer: B. Zn + 2 HCl → ZnCl₂ + H₂
1. Look for changes in oxidation number.
2. Zn: 0 → +2 (oxidised). H: +1 → 0 (reduced). So (B) is redox.
3. (A) acid–base neutralisation, no O.S. change.
4. (C) precipitation, no O.S. change.
5. (D) Lewis acid–base, no O.S. change.
_Source: syllabus Chem Ch 8 §8.1 Classifying Reactions as Redox_
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