Which statement best describes how to properly measure liquid volume using a graduated cylinder to ensure correct significant figures?

• A. Always round the measurement to the nearest whole number, regardless of the graduations.
• B. Read the volume at the bottom of the meniscus and estimate one digit beyond the smallest graduation.
• C. Record only the value shown exactly at the nearest graduation mark without estimating.
• D. Read the volume from the top of the meniscus and ignore any estimation.

Answer: (B)

Verified step by step guidance

1. Understand that a graduated cylinder is designed to measure liquid volume with a certain precision, indicated by the smallest graduation mark on the cylinder.
2. Recognize that the meniscus is the curved surface of the liquid in the cylinder, and the correct volume reading is taken at the bottom of this curve to avoid parallax errors.
3. Identify the smallest graduation on the cylinder, which tells you the precision of the measurement (for example, 1 mL, 0.1 mL, etc.).
4. Estimate one digit beyond the smallest graduation to account for uncertainty and ensure the correct number of significant figures. This means you read the volume at the bottom of the meniscus and then estimate the next decimal place.
5. Avoid rounding to the nearest whole number or ignoring the meniscus, as these practices reduce accuracy and do not reflect proper significant figure usage.