Here's how to determine the number of ions in potassium ferricyanide (K₃[Fe(CN)₆]):

1. Understanding the Formula:

* K₃: This indicates there are three potassium ions (K⁺)

* [Fe(CN)₆]³⁻: This represents a complex ion, where:

* Fe: Iron is in the +3 oxidation state (Fe³⁺)

* (CN)₆: Six cyanide ions (CN⁻) are coordinated to the iron ion.

2. Total Ions:

* Potassium ions: 3

* Complex ion: 1 (though it contains multiple ions within it)

Therefore, there are a total of 4 ions in potassium ferricyanide.