A chemist prepares a solution of potassium iodide by measuring out of potassium iodide into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's potassium iodide solution. Round your answer to significant digits.

0.169 mmol/L

Explanation:

A chemist prepares a solution of potassium iodide by measuring out 67.7 μmol of potassium iodide into a 400 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mmol/L of the chemist's potassium iodide solution. Round your answer to 3 significant digits.

Step 1: Convert potassium iodide from "μmol" to "mmol".

We will use the following conversion factors:

67.7 μmol × (1 mol / 10⁶ μmol) × (10³ mmol/1 mol) = 0.0677 mmol

Step 2: Convert the volume of solution from "mL" to "L"

We will use the conversion factor 1 L = 10³ mL.

400 mL × (1 L / 10³ mL) = 0.400 L

Step 3: Calculate the concentration of the solution in mmol/L

C = 0.0677 mmol / 0.400 L = 0.169 mmol/L