UPSC CSE Prelims 2002 Q110 — Science & Technology PYQ with Answer

Match List I (Oxidation number) with List II (The element) and select the correct answer using the codes given below the lists:

List I (Oxidation number) — List II (The element)

A. 2 —

1. Oxidation number of Mn in MnO₂

B. 3 —

2. Oxidation number of S in H₂S₂O₇

C. 4 —

3. Oxidation number of Ca in CaO₂

D. 6 —

4. Oxidation number of Al in NaAlH₄