A graduated cylinder is a commonly used piece of laboratory equipment for measuring the volume of a liquid sample. However, it should be noted that graduated cylinders are not highly accurate in volume measurement and should be used only to measure quantities of liquids other than limiting reagents. This is because the accuracy of the measurement is affected by several factors, such as the shape of the container and the surface tension of the liquid.
When using a graduated cylinder, it is important to note that the volume contained in the cylinder should be read from the bottom of the meniscus. The meniscus is the curved surface of a liquid in a container due to the adhesive forces between the liquid and the container. The volume of the liquid is read at the bottom of the meniscus to ensure an accurate measurement.
It is worth mentioning that graduated cylinders are not recommended for measuring reagents for microscale reactions due to their limited accuracy. However, a 5- or 10-mL graduated cylinder can be used for measuring volumes of extraction solvents greater than 1 mL. This is because the accuracy required for this type of measurement is not as critical as that required for microscale reactions.
In summary, graduated cylinders are useful for measuring the volume of a liquid sample but should be used with caution, especially when measuring limiting reagents. When using a graduated cylinder, it is important to read the volume at the bottom of the meniscus for accuracy. For microscale reactions, other equipment such as micropipettes should be used for more accurate measurements.