Final answer:
To measure and add 50 mL of a stock solution, a volumetric pipette or graduated cylinder should be used for accuracy and precision in chemical laboratory work, as volumetric flasks are not suitable for measuring out volumes other than their calibration capacity.
Step-by-step explanation:
If you need to add 50 mL of a stock solution to a reaction vessel, the most appropriate and precise piece of glassware to use would be ab this case. When dealing with stock solutions, it's important to use glassware that ensures precision to ensure the final concentrations of your solutions are accurate.
When mixing solutions or reagents, accuracy and precision are crucial, especially in a chemical laboratory or medical environment. For instance, preparing an IV solution with a specific concentration involves accurate measurements of the stock solution and addition of the solvent up to a desired volume. Misjudgements in the volume of stock solution added could alter the final concentration of the solution, which could have significant implications, for example, in medical applications.