MnO_2 + 4HCl -> MnCl_2 + 2H_2O + Cl_2. The reaction given above is a redox reaction because in this case:
- (a) MnO_2 is oxidised and HCl is reduced.
- (b) HCl is oxidised.
- (c) MnO_2 is reduced.
- (d) MnO_2 is reduced and HCl is oxidised.
Oxidation and reduction
Usually 2 marks a paper · mostly MCQs and short answers · asked in 2 of the last papers
Notes are being written
The board questions below are real and complete — they come from the CBSE papers themselves. The written notes for this topic are still being prepared.
Board questions on this topic
2 from the CBSE papers we hold — the exact wording the board used.
(a) Identify the reducing agent in the following reactions: (i) 4NH_3 + 5O_2 -> 4NO + 6H_2O (ii) H_2O + F_2 -> HF + HOF (iii) Fe_2O_3 + 3CO -> 2Fe + 3CO_2 (iv) 2H_2 + O_2 -> 2H_2O. (b) Define a redox reaction in terms of gain or loss of oxygen.