19. Of the following, which is the best tool for making an accurate and precise measurement of 21.7 mL of water?
Answer: C
A graduated cylinder is the best tool for making an accurate and precise measurement of 21.7 mL of water.
A graduated cylinder is specifically designed for measuring liquid volumes with a high degree of accuracy and precision, making it the most suitable choice for this measurement.
A) An eyedropper
An eyedropper is not suitable for measuring 21.7 mL accurately due to its small capacity and the difficulty in achieving precise measurements with it. Eyedroppers are typically used for transferring small volumes of liquid, usually in the range of a few drops.
B) A test tube
A test tube is not ideal for measuring specific volumes like 21.7 mL because it does not have graduated markings for precise measurement. While it can hold liquids, it lacks the accuracy required for exact volume measurement.
C) A graduated cylinder
A graduated cylinder is specifically calibrated to measure liquid volumes accurately. With clear markings and a narrow shape, it allows for precise readings, making it the best tool for measuring 21.7 mL of water.
D) A plastic beaker
A plastic beaker is generally used for mixing or holding liquids rather than for precise measurements. While it can hold 21.7 mL of water, the graduation marks are often less accurate than those found on a graduated cylinder, making it a less reliable choice for this specific measurement.
Conclusion
The graduated cylinder stands out as the most accurate and precise tool for measuring 21.7 mL of water due to its design and calibration. In contrast, the other options, such as the eyedropper, test tube, and plastic beaker, lack the necessary precision and accuracy for this specific task, making them unsuitable for measuring exact liquid volumes.