Which instrument is used to measure medium-small volumes of liquids?

• A. Beaker
• B. Graduated cylinder
• C. Serological pipette
• D. Volumetric flask

Answer: (C)

Focusing on measuring and transferring known, moderate-sized liquid volumes with accuracy is the key idea. A serological pipette is designed for this purpose: it has graduations along its length so you can measure and dispense a precise volume, and you can control the amount you transfer to another vessel. That makes it ideal for medium-small volumes.

The other tools don’t fit as well. A beaker is a general-purpose container used for rough pouring and mixing, not precise measurements. A graduated cylinder improves precision over a beaker but is typically used for larger volumes and isn’t as well suited for small, exact transfers. A volumetric flask is built for preparing a solution to a exact total volume, not for measuring out varying amounts of liquid.