Final answer:
To get an accurate measurement of liquid volume, the reading should be taken at the bottom of the meniscus using a level instrument and eye alignment to avoid errors. An example is an estimate of 21.6 mL if the meniscus lies between 21 and 22 mL marks and closer to 22.
Step-by-step explanation:
To accurately measure the volume of liquid in a graduated cylinder, the reading should be taken at the bottom of the meniscus. The meniscus is the curved surface of the liquid, and readings should be made at the lowest point of this curve. When observing the meniscus, ensure the measuring instrument is level and your eye is at the same level as the top of the liquid to avoid parallax error. For a more precise measurement, the distance between the major graduation marks should be subdivided mentally into tenths of a milliliter, and then an estimate made at the bottom of the meniscus.
For example, if the bottom of the meniscus lies between the 21 and 22 ml markings on the graduated cylinder, and appears to be closer to the 22-mL mark, a reasonable estimate of the liquid's volume would be 21.6 mL. The measured volume is always reported to the nearest 0.1 mL, which is the limit of precision for such an instrument with 1-mL divisions.