Which of the following is correctly paired?

Cyanide ion - CN^-

The correct answer is option 1. Cyanide ion - CN^-.

The correct pairing, "Cyanide ion \(CN^-\)", corresponds to the chemical formula and charge of the cyanide ion.

1. Cyanide Ion \((CN^-)\):

The cyanide ion is a polyatomic ion composed of one carbon (C) atom and one nitrogen (N) atom.

The chemical formula for the cyanide ion is \(CN^-\).

The cyanide ion carries a single negative charge (represented by the - sign).

2. Composition:

The cyanide ion has a triple bond between the carbon and nitrogen atoms, and it is a strong Lewis base.

The lone pair of electrons on the nitrogen atom makes the cyanide ion a potent ligand in coordination chemistry.

3. Comparison with Other Options:

Ammonia has the chemical formula \(NH_3\), and it is a neutral molecule. It does not have an \(OH^-\) ion. Bromide ion has the chemical formula \(Br^-\), and fluoride ion has the chemical formula \(F^-\). The charges and compositions in these pairs are not correct.

In summary, the correct pairing is "Cyanide ion \(CN^-\)", as it accurately represents the chemical formula and charge of the cyanide ion.