Question

Question #d7700

Answer 1

Polyatomic ions are charged chemical species composed of two or more covalently bonded atoms that are considered to act as a single unit.

The nitrite ion, or `"NO"_2^(-)`, is composed of one nitrogen atom, `"N"`, and two oxygen atoms, `"O"_2`, arranged with an imbalance of 1 electron, hence the negative charge.

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The nitrite ion will form ionic bonds with a variety of positively charged ions (or cations) due to the electrostatic attraction between the negative and the positive charges.

Compounds formed by `"NO"_2^(-)` include

Sodium nitrite - `NaNO_2` - formed when the `Na^(+)` cation is ionically bonded to the `NO_2^(-)` anion;

Magnesium nitrite - `Mg(NO_2)_2` - formed when a `Mg^(2+)` cation if bonded to the nitrite anion;

Barium nitrit - `Ba(NO_2)_2` - formed when a `Ba^(2+)` cation bonds with the nitrite anion;

Potassium nitrite - `KNO_2` - formed when a `K^(+)` cation bonds with the nitrite anion.

Here's a link to a list containing more compounds formed by the nitrite polyatomic ion

http://www.endmemo.com/chem/common/nitrite.php

A link to an answer on how polyatomic ions bond posted by other contributors:

http://socratic.org/questions/how-do-polyatomic-ions-bond
http://socratic.org/questions/how-do-polyatomic-ions-form-compounds