Question

What is the name of `CoF_2`?

Answer 1

Cobalt Floride. or Cobalt diFloride.

Explanation:

The most common form of Cobalt has a charge of +2 so can bond with two Florine atoms.

To be more precise this compound could be named Cobalt +2 Floride . A more common name would be Cobalt di Floride.

Answer 2

The name is cobalt(II) fluoride.

Explanation:

Cobalt is in the `"d"`-block of elements, so it is a transition metal.

Here are the steps for deriving the name of a compound of a transition metal.

Step 1. Write the name of the transition metal

This gives: "cobalt".

Step 2. Add the name of the nonmetal with the ending "-ide"

This gives: "cobalt fluoride".

Step 3. Use the charge on the non-metal to find the charge on the transition metal

The charge on each `"F"` is -1, for a total charge of -2.

The charge on the `"Co"` must be +2.

Step 4. Write the charge on the non-metal as Roman numerals in parentheses immediately after (no spaces) the name of the metal.

This gives the name: cobalt(II) fluoride.