Preparing a standard solution of a specific molarity requires a series of precise laboratory steps to ensure accuracy. First, the technician accurately weighs the solid solute on an analytical balance. The weighed solute is then transferred into a clean beaker, where a small volume of distilled water is added. The mixture is stirred gently with a glass rod until the solid is completely dissolved. Following dissolution, the liquid is carefully poured through a funnel into a volumetric flask of the desired volume. To guarantee that no solute is left behind, the beaker and glass rod must be rinsed multiple times with distilled water, and these washings must be added directly to the flask. Next, the technician adds distilled water to the flask until the level approaches the graduation mark on the neck. Using a Pasteur pipette, water is added dropwise until the bottom of the meniscus is exactly aligned with the mark. Finally, the flask is stoppered and inverted several times to ensure the solution is thoroughly mixed and homogeneous. Skipping the rinsing step, or failing to add the rinsings to the flask, will result in an inaccurate, lower concentration than intended.
According to the passage, what is the direct consequence of failing to rinse the beaker and add the washings to the volumetric flask?
- AThe solid solute will not dissolve completely when water is added.
- The final concentration of the standard solution will be lower than intended.Answer
- CThe bottom of the meniscus will fail to align with the graduation mark.
- DThe solution will remain unmixed and non-homogeneous after inversion.