In preparing a QT solution with non-readily soluble dry chemicals, what is the first step?

Assembling and labeling glassware is the most appropriate first step when preparing a quantitative (QT) solution, especially with non-readily soluble dry chemicals. This step is essential for ensuring that the correct apparatus is in place and properly identified before any chemical handling begins. By setting up and labeling the glassware, you create a clear, organized environment which minimizes the risk of cross-contamination and confusion during the preparation process.

Establishing the proper glassware setup also allows you to prepare for the specific needs of the solution in question—ensuring that you are equipped with the necessary equipment to effectively dissolve the chemical in a controlled manner. This foundational step is crucial for maintaining accuracy in the preparation of the solution, as having labeled containers helps avoid mistakes regarding measurements or the types of chemicals used in the experiment.

Once the glassware is assembled and labeled, the subsequent steps—transferring the chemical, adding the solute, and stirring—can be executed with a clear focus on accuracy and safety.