Final answer:
The molarity of the solution is 0.556 M.
Step-by-step explanation:
The molarity (M) of a solution is calculated by dividing the number of moles of solute by the volume of the solution in liters. In this case, we have 0.50 moles of KI dissolved in 900 ml (or 0.900 L) of solution. To calculate the molarity, we divide the number of moles by the volume:
Molarity (M) = moles of solute / volume of solution (L)
Molarity = 0.50 moles / 0.900 L = 0.556 M