Which of the following lists the correct steps for preparing a solution of known concentration in a laboratory setting?

• A. Add solvent to a volumetric flask, weigh the solute, and pour it directly into the flask without dissolving.
• B. Mix the solute and solvent in any container, then measure the final volume.
• C. Weigh the solute, dissolve it in a small amount of solvent, transfer to a volumetric flask, and dilute to the mark.
• D. Weigh the solute, add it to the solvent, and heat until boiling.

Answer: (C)

Verified step by step guidance

1. Step 1: Accurately weigh the required amount of solute using an analytical balance to ensure the desired concentration can be achieved.
2. Step 2: Transfer the weighed solute into a clean container and dissolve it in a small volume of solvent. This helps to ensure the solute is fully dissolved before final dilution.
3. Step 3: Pour the dissolved solute solution into a volumetric flask, which is designed to measure precise volumes.
4. Step 4: Add solvent gradually to the volumetric flask until the bottom of the meniscus reaches the calibration mark on the neck of the flask, ensuring the total volume is accurate.
5. Step 5: Stopper the flask and invert it several times to mix the solution thoroughly, ensuring uniform concentration throughout.