72. Preparing a Solution of Known Solute Molarity … in the Lab

In this video, we outline the steps necessary to prepare a solution of known solute molarity in the laboratory. The target volume and molarity of the solution must be known to determine the approximate mass of solute necessary. Using an analytical balance, we accurately (hopefully) and precisely mass the solute and transfer the solute into a volumetric flask. A volumetric flask is a glass flask that has been calibrated to contain an accurate and precise volume of liquid. Enough solvent is added to gently swirl and dissolve the solute. Solvent is then added to the volumetric line on the flask and the solution inverted many times to ensure proper mixing. The concentration of solute is then calculated based on the actual mass transferred into the volumetric flask. 00:00 Goal: prepare 50.00 mL of a 0.0500 M solution of copper(II) sulfate 01:06 Determine mass of solute necessary 04:56 Step 1: obtain a volumetric flask 06:53 Step 2: mass required amount of solute on a balance 09:34 Step 3: transfer solute to volumetric flask 11:03 Step 4 and 5: record solute mass and start dissolving solute 12:30 Step 6 and 7: fill flask to volumetric line with solvent and mix well 13:48 Determine solute molarity based on solute mass