Identify the reducing agent in the following reactions.
(a) `4NH_(3)+5O_(2)to4NO+6H_(2)O" "(b) H_(2)O+F_(2)toHF+HOF`
`(c)Fe_(2)O_(3)+3COto2Fe+3CO_(2)" "(d) 2H_(2)+O_(2)to2H_(2)O`

Explanation

(a) Ammonia `(NH_(3))` is the reducing agent. It has reduced oxygen `(O_(2))` which acts as oxidising agent.
(b) Water `(H_(2)O)` is the reducing agent. It has reduced fluorine `(F_(2))` which acts as oxidising agent.
(c) Carbon monoxide (CO) is the reducing agent. It has reduced ferric oxide `(Fe_(2)O_(3))` which acts as oxidising agent.
(d) Hydrogen `(H_(2))` is the reducing agent. It has reduced oxygen `(O_(2))` which acts as oxidising agent.