---
title: "A student prepares a calibration curve of absorbance versus concentration for \\(\\text{CuSO}_4\\text{(aq)}\\) using a spectrophotometer set to an appropriate wavelength. While measuring the unknown sample, the student forgets to wipe fingerprints and water droplets off the outside of the cuvette. Which of the following best explains how this error affects the calculated concentration of the unknown solution?"
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url: "https://nerd-notes.com/ubq/119288/"
date_modified: "2026-08-19T12:39:40+00:00"
---

# A student prepares a calibration curve of absorbance versus concentration for \(\text{CuSO}_4\text{(aq)}\) using a spectrophotometer set to an appropriate wavelength. While measuring the unknown sample, the student forgets to wipe fingerprints and water droplets off the outside of the cuvette. Which of the following best explains how this error affects the calculated concentration of the unknown solution?

A student prepares a calibration curve of absorbance versus concentration for \(\text{CuSO}_4\text{(aq)}\) using a spectrophotometer set to an appropriate wavelength. While measuring the unknown sample, the student forgets to wipe fingerprints and water droplets off the outside of the cuvette. Which of the following best explains how this error affects the calculated concentration of the unknown solution?

- **A.** The calculated concentration will be falsely lower because less light reaches the detector, which is recorded as a lower absorbance value.
- **B.** The calculated concentration will be falsely lower because water droplets on the cuvette dilute the solution inside, decreasing the concentration of solute particles.
- **C.** The calculated concentration will be falsely higher because scattering of light by the surface residue reduces light reaching the detector, producing a higher absorbance value.
- **D.** The calculated concentration will be falsely higher because the residue increases the light path length, which increases the molar absorptivity of the solute.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119288/*