using molarity to find solute moles and solution volume

Question

A chemist adds 145.0 mL of a 2.6 M potassium iodide (KI) solution to a reaction flask. Calculate the millimoles of potassium iodide the chemist has added to the flask. Round your answer to 2 significant digits.

Answer 1

This is straightforward from the definition of molarity = moles/volume of solution. 2.6 M = (moles of KI) / (145.0 mL KI) --> 2.6 (145.0 mL) = 380 milli-moles of KI (to 2 sig figs).