The number of ions is determined by multiplying the given volume and the molarity of the solution. The product is multiplied to the number of ions when the solution dissociates. In this case:
1. 200.0 mL of 0.10 M iron (III) chloride = 0.2*0.1* 4 = 0.08
2. 800.mL of 0.10 M sucrose = 0.8 * 0.1 * 1 = 0.08
The two solutions have the same number of ions.
