1. Identify the Charges:
* Cobalt(II) ion (Co²⁺) has a +2 charge.
* Nitrite ion (NO₂⁻) has a -1 charge.
2. Determine the Ratio:
To achieve a neutral compound, we need to balance the charges. Since the charges are not the same, we need to find the least common multiple (LCM) of 2 and 1, which is 2.
* To get a +2 charge from cobalt, we need one Co²⁺ ion.
* To get a -2 charge from nitrite, we need two NO₂⁻ ions.
3. Write the Formula:
The formula of the compound is Co(NO₂)₂.
Explanation:
* Co: Represents one cobalt ion.
* (NO₂)₂: Represents two nitrite ions enclosed in parentheses to indicate that the entire nitrite group appears twice.
Therefore, the compound formed between Co²⁺ and NO₂⁻ is cobalt(II) nitrite, with the formula Co(NO₂)₂.
