Question

if fingerprints were left on the cuvette, how would that affect the absorbance read?
transmittance $(t)=\frac{i_{t}}{i_{o}}$
absorbance $(a)=-\log (t)=-\log \left(\frac{i_{t}}{i_{o}}\
ight)$
the fingerprint would scatter the light, causing a higher absorbance.
the fingerprint would scatter the light, causing a lower absorbance.
the fingerprint would increase the concentration, causing a higher absorbance.
the fingerprint would decrease the concentration, causing a lower absorbance.

Explanation:

Fingerprints on the cuvette scatter light. According to the formula \(A =-\log(T)=-\log(\frac{I_{t}}{I_{o}})\), when light is scattered, \(I_{t}\) (transmitted light intensity) decreases. Since \(A =-\log(\frac{I_{t}}{I_{o}})\), a decrease in \(I_{t}\) makes \(\frac{I_{t}}{I_{o}}\) smaller. The logarithm of a smaller positive number (since \(0<\frac{I_{t}}{I_{o}}\leq1\)) is more negative, and with the negative sign in \(A =-\log(\frac{I_{t}}{I_{o}})\), the absorbance \(A\) increases. Fingerprints do not change the actual concentration of the sample in the cuvette.

Answer:

The fingerprint would scatter the light, causing a higher absorbance.