🧪 Chemistry by Chang – Problem 1.25 | Precision and Accuracy | Steemit Science

in Popular STEM20 hours ago

Hello Steemit learners! 👋📏

This exercise comes from Raymond Chang’s Chemistry (14th Edition), in Chapter 1: Measurement and the Properties of Matter. It focuses on two fundamental ideas in experimental science: precision and accuracy.


🔹 Problem 1.25:

Three students (A, B, and C) are asked to determine the volume of a sample of ethanol. Each student measures the volume three times with a graduated cylinder. The results in milliliters are:

  • A: (87.1, 88.2, 87.6)
  • B: (86.9, 87.1, 87.2)
  • C: (87.6, 87.8, 87.9)

The true volume is 87.0 mL.

👉 Comment on the precision and the accuracy of each student’s results.


This problem is excellent for reflecting on how measurements can be:

  • Precise: values are close to each other (little variation).
  • Accurate: values are close to the true value.

Understanding the difference between the two is critical in any laboratory setting.


📸 Here’s my complete analysis of each student’s results:

Captura desde 2025-08-26 18-43-22.png


Which do you think matters more in the lab: precision or accuracy? Let’s discuss in the comments! 🧠💬

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