88. Which of the following is the best procedure for measuring liquid in a graduated cylinder?
Answer: D
Place the cylinder on a level surface and read the bottom of the meniscus at eye level.
To accurately measure liquid in a graduated cylinder, it is essential to place the cylinder on a level surface and read the bottom of the meniscus at eye level. This method ensures that parallax errors are minimized and that the measurement is as precise as possible.
A) Place the cylinder on a level surface and read the top of the meniscus at eye level
This option is incorrect because reading the top of the meniscus can lead to inaccuracies. The meniscus is typically concave due to surface tension, and the bottom of the meniscus provides the correct measurement for liquid volumes.
B) Hold the cylinder at eye level and read the bottom of the meniscus
While this option includes reading the bottom of the meniscus correctly, holding the cylinder instead of placing it on a level surface can introduce errors due to hand movement or tilting. Stability is crucial for accurate measurement.
C) Hold the cylinder at eye level and read the top of the meniscus
This choice is also incorrect as it suggests reading the top of the meniscus, which is not the standard practice for measuring liquids accurately. Additionally, holding the cylinder can lead to instability in the reading.
D) Place the cylinder on a level surface and read the bottom of the meniscus at eye level
This option is correct as it combines both the proper positioning of the graduated cylinder and the appropriate point of measurement. By ensuring the cylinder is on a flat surface and reading at eye level, the measurement is both accurate and reliable.
Conclusion
The correct procedure for measuring liquid in a graduated cylinder emphasizes the importance of stable positioning and accurate reading techniques. Option D effectively incorporates both elements, ensuring that the measurement reflects the true volume of liquid. All other options either fail to provide stability or suggest an incorrect reading point, leading to potential inaccuracies in measurement.