Redox Reactions Ques 3
3. Phosphorus has the oxidation state of $+3$ in
[1994]
(a) Phosphorous acid
(b) Orthophosphoric acid
(c) Hypophosphorous acid
(d) Metaphosphoric acid.
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Answer:
Correct Answer: 3.(a)
Solution:
- (a) $O.N.$ of $P$ in $H_3 PO_3$ (phosphorous acid)
$3 \times 1+x+3 \times(-2)=0$ or $x=+3$
In orthophosphoric acid $(H_3 PO_4)$ $O.N.$ of $P$ is $+5$ , in hypophosphorous acid $(H_3 PO_2)$ it is $+1$ while in metaphosphoric acid $(HPO_3)$, it is $+5$ .
BETA
