Which one of the following statements is correct?
[amp_mcq option1=”The oxidation number for hydrogen is always zero.” option2=”The oxidation number for hydrogen is always +1.” option3=”The oxidation number for hydrogen is always -1.” option4=”Hydrogen can have more than one oxidation number.” correct=”option4″]
This question was previously asked in
UPSC CDS-2 – 2016
Hydrogen can exist in different chemical environments where it exhibits more than one oxidation number.
The oxidation number for hydrogen is typically +1 when bonded to nonmetals (e.g., H₂O, HCl, NH₃). However, when bonded to more active metals (forming metal hydrides like NaH, CaH₂), hydrogen is more electronegative than the metal and has an oxidation number of -1. In its elemental form (H₂), the oxidation number is 0.