In a chemistry laboratory, what is the meniscus and how should it be used to accurately measure the volume of a liquid in a graduated cylinder?

• A. The meniscus is the flat surface of a liquid; to measure accurately, read the volume at the top edge of the liquid.
• B. The meniscus is the curved surface of a liquid; to measure accurately, read the volume at the bottom of the meniscus at eye level.
• C. The meniscus is the line formed by the liquid and the container; to measure accurately, read the volume from any angle.
• D. The meniscus is the curved surface of a liquid; to measure accurately, read the volume at the top of the meniscus from above.

Answer: (B)

Verified step by step guidance

1. Understand that the meniscus is the curved surface of a liquid in a container, caused by the liquid's adhesion to the container walls and cohesion within the liquid itself.
2. Recognize that in most liquids like water, the meniscus curves downward (concave), while in some liquids like mercury, it curves upward (convex).
3. To measure the volume accurately in a graduated cylinder, position your eye level with the meniscus to avoid parallax error, which occurs when viewing from above or below.
4. Read the volume at the bottom of the meniscus (the lowest point of the curve) for liquids like water, as this is the standard reference point for volume measurement.
5. Avoid reading the volume from the top of the meniscus or from an angle, as this will lead to inaccurate measurements.