Q1. [1] § 1.1.2 Balanced Chemical Equations § 1.2.1 Combination Reaction § 1.2.4 Double Displacement Reaction
Study the following chemical reaction :
2 Na (s) + 2 H₂O (l) → 2 NaOH (aq) + H₂ (g)
The reducing agent in this reaction is :
- (a) Na
- (b) H₂O
- (c) NaOH
- (d) H₂
Previously asked in CBSE board exam
2023 31/5/1 Q3
Generated by claude-sonnet-4-6 · 2026-06-14 10:29 · grounding rag
Model Answer
(a) Na
Na is the reducing agent because it loses electrons (gets oxidised from 0 to +1), thereby reducing hydrogen in water from +1 to 0 (H₂).
Explanation
The reducing agent is the substance that itself gets oxidised (loses electrons) and causes reduction in another substance. Here, Na goes from oxidation state 0 → +1 (oxidised), so Na is the reducing agent. H₂O is the oxidising agent (hydrogen in it is reduced from +1 → 0). Examiners expect you to identify the correct substance and briefly justify using oxidation states or electron transfer.
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