Question

A powerful oxidant among the following is.
A.Hypochlorite ion
B.Chlorite ion
C.Chlorate ion
D.Perchlorate ion

Answer 1

Hint: Oxidizing agents are the compound/group that oxidizes other compounds thereby reducing itself. The greater the oxidation number, the lesser will be the power of the oxidant. Since oxidants undergo reduction while oxidizing other compounds and it leads to a lower oxidation number.In oxychloride compounds, the oxidation number of chlorine decides its oxidizing power.

Complete step by step answer:
The powerful oxidant among the oxychloride ions is (A).
(A)Generally, the lesser the oxidation number, the greater will be the oxidizing power. Let “x” be the oxidation number of chlorine. It is known that the oxidation number of hydrogen is $ + 1$ and the oxidation number of oxygen is $- 2$
The molecular formula for hypochlorite ion is $OCl^-$. The oxidation state of chlorine in hypochlorite ion can be determined as,
$ \Rightarrow - 2 + x = - 1$
$x = - 1 + 2$
$ \Rightarrow x = + 1$
Thus, the oxidation number of chlorine in sodium hypochlorite ion is $ + 1$
(B)Generally, the lesser the oxidation number, the greater will be the oxidizing power. Let “x” be the oxidation number of chlorine. It is known that the oxidation number of hydrogen is $ + 1$and the oxidation number of oxygen is $ - 2$
The molecular formula for chlorite ion is $Cl{O_2}^ - $. The oxidation state of chlorine in chlorite ion can be determined as,
$ \Rightarrow x + 2( - 2) = - 1$
$x = - 1 + 4$
$ \Rightarrow x = + 3$
Thus, the oxidation state of chlorine in chlorite ion is $ + 3$
(C)Generally, the lesser the oxidation number, the greater will be the oxidizing power. Let “x” be the oxidation number of chlorine. It is known that the oxidation number of hydrogen is $ + 1$ and the oxidation number of oxygen is $ - 2$
The molecular formula for chlorate ion is $Cl{O_3}^ - $. The oxidation state of chlorine in chlorate ion can be determined as,
$ \Rightarrow x + 3( - 2) = - 1$
$x = - 1 + 6$
$ \Rightarrow x = + 5$
Thus, the oxidation state of chlorine in chlorate ion is $ + 5$
(D)Generally, the lesser the oxidation number, the greater will be the oxidizing power. Let “x” be the oxidation number of chlorine. It is known that the oxidation number of hydrogen is $ + 1$ and the oxidation number of oxygen is $ - 2$
The molecular formula for perchlorate ion is $Cl{O_4}^ - $. The oxidation state of chlorine in perchlorate ion can be determined as,
$ \Rightarrow x + 4( - 2) = - 1$
$x = - 1 + 8$
$ \Rightarrow x = + 7$
Thus, the oxidation state of chlorine in perchlorate ion is $ + 7$
So the correct answer is choice A.

Note:
Alternate approach: It is known that oxygen is more electronegative than chlorine. The oxidizing power of oxychloride compounds will be determined by the ease of removal of $C{l^ - }$when terminal oxygen compound increases, then the ease of removal of $C{l^ - }$ is difficult.
Among the given oxychloride ions, perchlorate $(ClO{{}_{_4}^ - })$ has 4 terminal oxygen atoms. Thus, the removal of $C{l^ - }$ is difficult in perchlorate ion since four oxygen atoms attract the $O - Cl$ bonds towards itself. Hypochlorite ion $(Cl{O^ - })$ has one terminal oxygen atom. Thus, the removal of $C{l^ - }$ from hypochlorite ions is easy when compared to other oxychloride ions.