Answer:
[Cl⁻] = 1.2 M
Step-by-step explanation:
Equation of the disssociation of Iron (II) chloride is given below:
FeCl₃ -------> Fe³⁺ + 2Cl⁻
from the dissociation equation, 3 moles of Cl ions are produced from the dissociation of FeCl₃.
In a 0.40 M solution of FeCl₃, the concentration of Cl⁻ ions will be 0.40 * 3 = 1.20 M
Therefore, the concentration of Cl⁻ ions, [Cl⁻] = 1.2M