What would a chemist use to measure exactly 25.5 cm^3 of dilute hydrochloric acid? A) Burette, B) Beaker, C) Measuring cylinder, or D) Pipette?
The beaker would not be good because it is hard to measure accurately to a millimeter. Pipettes generally are used to dispense liquids by the drop and not for actually measuring the volume of a liquid.
Both measuring cylinders (also called graduated cylinders) and burettes can be used to measure volume. With a graduated cylinder you add the liquid to the cylinder and read the volume on the gradation lines etched into the side of the cylinder. Depending on the cylinder you could accurately measure your volume this way.
If you want to accurately measure the volume of a liquid you are putting into another container, then the burette would be the best choice. Burettes are used, for example, to do acid-base titrations, and can measure the volume of liquid released with great precision.
The advantage with the burette is that you put the liquid into the burette, measure its initial volume, and then dispense the liquid to get an exact amount. If you put exactly 25.5 ml in a graduated cylinder and then transfer it to another container some of the liquid will remain in the cylinder due to surface tension so you will not have the exact amount you started with.
Overall, the burette will give you the most exact measurement of any volume you want.
Correct answer to the question is option C.
A measuring cylinder is used to measure given volumes of liquids. It is suitable for measurement of any given quantity of liquid subject to the maximum of capacity of the cylinder which is usually of the order of one or one half of a liter.
A burette is used when small quantities of liquids taken from a given quantity of liquids are to be measured out.
A beaker does not have any graduations for measurement of volume. It can at best be used to measure out approximate quantities of liquid.
Pipette is used for measuring out accurately fixed volumes of liquids according to the size of the pipette. Thus a pipette may have capacity in round figures such as 25 cm^2 or 50 cm^2. These are not available in odd capacities such as 25.5 cm^2.