Question

What polyatomic ion has positive charge?
A) Anion
B) Cation
C) Free radical
D) All of the above

Answer 1

We have to remember that the molecules don’t have charges in them they have a net charge of 0, whereas polyatomic ions have charges in them whether positive or negative but they do have charge in them.

Complete answer:
We are going to learn about polyatomic ions first.
When atoms or sets of atoms which are covalently bonded together to form a single unit and have a net charge on them, this refers to polyatomic ions.
This species has a charge on it unlike molecules as it has zero charge whereas free radical has unpaired electrons in them.
For example: Chlorine molecule ($C{l_2}$) has zero charge
Whereas
Chloride ion $\left( {C{l^ - }} \right)$has a negative charge.
Polyatomic ions can be of different classes out of which one is cation and other is Anion explanation is as follows:
Cation is a positively charged species, which has lost one or more electrons, gaining a positive charge, also we can define cation as the species that loses its electron.
Example: $N{a^ + },{K^ + },C{u^{2 + }}$
As the definition of cation says, $Na$ metal lose its one electron to form $N{a^ + }$
$N{a^ + } \to Na + {\text{ }}{e^ - }$
Similarly for K.
But for $Cu$: As it lose $2$ electrons to form $C{u^{2 + }}$
$C{u^{2 + }} \to Cu + 2{e^ - }$
Anion is a negatively charged species, which gains one or more than one electron, acquiring a negative charge. Also, we can define anion as the species that gains an electron.
Example: $C{l^ - },S{O_4}^{2 - }$
Chlorine molecule gains an electron to form Chloride ion.
$C{l_2} + 2{e^ - } \to C{l^ - }$
Option A) this is an incorrect option as a polyatomic ion having negative species is called Anion as we have discussed above.
Option B) this is a correct option since a polyatomic ion having a positive charge is Cation.
Option C) this is an incorrect option as Free radicals are the species having an unpaired electron.
Option D) this option is incorrect as we got the correct answer for this question.

Note:
We have to remember that the cation is a polyatomic ion having positive charge, Anion is a polyatomic ion having negative charge and free radicals are the species having an unpaired electron in them.