Question

Law enforcement uses a quick and easy test to detect the presence of the illicit drug PCP by reacting it with potassium iodide. The PCP will form a crystalline solid with a long branching needle-like structure with KI. What is the molarity of KI in a stock solution prepared by dissolving 390.1 g of KI to a total volume of 140.0 mL?

Answer 1

16.79 M

Step-by-step explanation:

Given data

• Mass of KI (solute): 390.1 g

• Volume of solution: 140.0 mL = 0.1400 L

First, we will calculate the moles of KI, considering its molar mass is 166.00 g/mol.

390.1 g × (1 mol/166.00 g) = 2.350 mol

The molarity of KI is:

M = moles of solute / liters of solution

M = 2.350 mol / 0.1400 L

M = 16.79 M