Identify from the following reactions the reactants that undergo oxidation and reduction

Question

6. Identify from the following reactions the reactants that undergo oxidation and reduction.

a. Fe + S  →  FeS

b. 2Ag₂O   →    4Ag + O₂

c. 2Mg + O₂ →   2MgO

d. NiO + H₂   →  Ni + H₂O

Answer 1

A. Fe + S  →  FeS

Here , Fe is oxidised from 0 to +2, while S is reduced from 0 to -2 
Fe undergoes oxidation (as losing electrons)
Sulphur undergoes reduction (as accepting electrons)

B. 2Ag₂O   →    4Ag + O₂

Ag  in  Ag₂O is reduced from +1 to 0, and oxygen  Ag₂O  is oxidised from -2 to 0 
O undergoes oxidation (as losing electrons)
Ag undergoes reduction (as accepting electrons) 

C. 2Mg + O₂ →   2MgO

Mg is oxidised from 0 to +2, and  O is reduced from 0 to -2
Mg undergoes oxidation (as losing electrons)
O₂ undergoes reduction (as accepting electrons)

D. NiO + H₂   →  Ni + H₂O

Ni is reduced from +2 tp 0, and H is oxidised from 0 to +1
H undergoes oxidation (as losing electrons)
Ni undergoes reduction (as accepting electrons)