Name one example of a reaction in which dihydrogen acts (i) as an oxidising agent and (ii) as a reducing agent.

Explanation

Oxidising agent : `2Na + H_(2) to 2Na^(+)H^(-)`. Here, Na is oxidised to `Na^(+)`
Reducing agent `CuO + H_(2) overset("Heat")to Cu + H_(2)O`. Here, CuO is reduced to Cu.