Consider the following reaction:
The values of x, y and z in the reaction are, respectively:
(1) 5, 2 and 16 (2) 2, 5 and 8 (3) 2, 5 and 16 (4) 5, 2 and 8
[JEE Main 2013]
Solution
We have, 
[Reduction]
[Oxidation]
On balancing,
………….(1)
………….(2)
2. (1) + 5. (2)
So, 
Balancing O and H considering acidic medium (since H+ is mentioned),
x = 2, y = 5, z = 16
Hence, (3).