Question

Which of the following act as reducing agents?
(i) $PO _{4}^{3-}$
(ii) $SO _{3}$
(iii) $PO _{3}^{2-}$
(iv) $NH _{3}$

• A. (i), (ii) and (iii)
• B. Only(iii)
• C. (i), (iii) and (iv)
• D. (iii) and (iv)

Answer 1

Answer: (D)

In (i) and (ii), both P and S are in highest oxidation state. In (iii) and (iv); $P$ has oxidation state of $+4$ which can be oxidized to $+5$ state, while in case of $NH _{3}$, nitrogen has oxidation state of $-3$ which can be oxidised.