When reading a meniscus in a graduated cylinder, you should measure from which part of the curve?

• A. Measure from the top of the curve
• B. Measure from the bottom of the curve
• C. Measure from the middle of the curve
• D. Ignore the curve and read the scale directly

Answer: (B)

Reading a meniscus correctly hinges on how the liquid surface curves because of adhesion to the container. In a typical graduated cylinder, liquids like water form a concave curve, dipping a little in the middle. The actual liquid level is where that curved surface meets the scale, which is at the bottom of the curve. So you read from the bottom of the meniscus, with your eye level with that point to avoid parallax. Reading from the top, the middle, or ignoring the curve wouldn’t match where the surface actually sits.