Final answer:
In a lab, it's important to use calibrated pipettes for accurate volume measurement. Precise instruments like micropipettes and volumetric pipettes are essential, and proper documentation is key for reproducibility.
Step-by-step explanation:
Understanding Laboratory Measurements
When performing laboratory experiments, accurate measurement of liquids is vital. The pipette mentioned has a volume of 2.5 ml, which may refer to a volumetric pipette or it could be an adjustable volume micropipette. For calibration, the pipette should be checked against known volumes to ensure its accuracy. The beaker used in conjunction with the pipette should also be calibrated; however, beakers are generally less precise than pipettes. When reading volumes from a beaker or pipette, make sure to view the liquid at eye level and read the bottom of the meniscus for water-based solutions or at the top for more viscous solutions.
Laboratory instruments like micropipettes are designed for precise measurements of smaller volumes, typically in the micro-liter range. Volumetric pipettes, on the other hand, are perfect for accurately measuring a fixed volume like 2.5 ml. For even more precision, a UV/vis spectrophotometer and standard quartz cuvette can sometimes be used for measuring the absorbance of a solution, which can be correlated with concentration according to Beer's Law.
Finally, always document the measurement process carefully, recording your name, date, volumetric readings, and any calibrations made to ensure reproducibility and traceability of the results.