Ch.1 - Chemical Tools: Experimentation & Measurement

McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook

McMurry 8th Edition

Ch.1 - Chemical Tools: Experimentation & Measurement

Problem 30

Chapter 1, Problem 30

Assume that you have two graduated cylinders, one with a capacity of 5 mL (a) and the other with a capacity of 50 mL (b). Draw a line in each, showing how much liquid you would add if you needed to measure 2.64 mL of water. Which cylinder will give the more accurate measurement? Explain.

Name: Chemistry
Author: McMurry
ISBN: 9781292336145

Verified step by step guidance

Identify the two graduated cylinders: one with a capacity of 10 mL (left) and the other with a capacity of 5 mL (right).

Determine the scale of each graduated cylinder. The 10 mL cylinder has increments of 0.2 mL, and the 5 mL cylinder has increments of 0.1 mL.

To measure 2.64 mL of water, locate the 2.6 mL mark on the 5 mL cylinder and add a small amount to reach 2.64 mL. This cylinder allows for more precise measurement due to smaller increments.

On the 10 mL cylinder, locate the 2.6 mL mark and estimate the additional 0.04 mL. This cylinder is less precise due to larger increments.

Conclude that the 5 mL graduated cylinder will give a more accurate measurement of 2.64 mL of water because it has finer scale increments, allowing for more precise readings.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Graduated Cylinder Accuracy

Graduated cylinders are designed to measure liquid volumes accurately. The accuracy of a graduated cylinder depends on its size and the smallest division marked on it. A smaller cylinder, like the 5 mL one, typically has finer graduations, allowing for more precise measurements compared to a larger cylinder with broader divisions.

Meniscus Reading

When measuring liquid in a graduated cylinder, the meniscus, or the curve of the liquid's surface, must be read at eye level. The correct reading is taken at the bottom of the meniscus, which can help avoid parallax errors. This technique is crucial for ensuring that the measurement is as accurate as possible.

Volume Measurement Precision

Precision in volume measurement refers to the ability to consistently reproduce a measurement. In this context, using a 5 mL graduated cylinder to measure 2.64 mL will yield a more precise result than using a 50 mL cylinder, as the smaller cylinder's scale allows for finer adjustments and reduces the relative error in the measurement.

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