If a sample tube was smudged with a fingerprint when inserted into a spectrometer, what affect would this have on the value of A (absorbance) when you read it? explain.
hmmmm.....look it up on google, do you know anything about the Wright Brothers?
I suspect that the absorbance would increase. The fingerprint would cause the light going through the cuvette to be distorted somewhat. This would lead to less light hitting the detector and thus, a higher absorbance.
I agree with Christina. Depending upon the wavelength, not only could the light be distorted (resulting in apparent absorbance) BUT some could be absorbed due to the oil, especially in the ultraviolet region.
When a sample tube is smudged with a fingerprint and then inserted into a spectrometer, it can have an impact on the measurement of absorbance (A) obtained from the spectrometer reading. The effect of the smudge on the absorbance value depends on several factors, including the nature of the smudge, the wavelength of light used in the spectrometer, and the level of absorbance of the smudge itself.
Typically, a spectrometer measures the amount of light absorbed by a sample to calculate its absorbance. The sample is usually placed in a cuvette or a tube, which allows the light to pass through the sample. The spectrometer measures the intensity of the transmitted light and compares it to the intensity of the incident light. The absorbance is calculated using the equation: A = -log(T), where T represents the transmittance (ratio of transmitted light to incident light).
Now, if a smudge, such as a fingerprint, is present on the sample tube, it can interfere with the transmission of light through the sample. The smudge may cause scattering or attenuation of the light, reducing the amount reaching the detector. As a result, the measured transmittance will be lower than it should be, leading to an overestimation of absorbance.
Furthermore, the effect of the smudge on the absorbance value will depend on the wavelength of light used in the spectrometer. Different substances interact differently with light at various wavelengths. If the smudge absorbs light at the specific wavelength used for measurement, it may lead to an increase in absorbance. On the other hand, if the smudge scatters or reflects the light, it may result in a decrease in absorbance.
It is important to note that the impact of the smudge on the absorbance value might not be solely due to the smudge itself. The presence of the smudge could also affect the accuracy and reproducibility of measurements if it introduces variability in the positioning or alignment of the sample within the spectrometer.
To minimize the effects of smudges or fingerprints, it is crucial to ensure clean and uncontaminated sample tubes or cuvettes. Regular cleaning of the tubes using appropriate cleaning agents or solvents, such as ethanol, can help prevent smudging and ensure accurate measurements.