Which formula correctly describes the relationship between absorbance and %T?

The relationship between absorbance (A) and percent transmittance (%T) is grounded in the principles of light absorption and transmission in a sample. Absorbance is related to transmittance, which is the measure of the amount of light that passes through a sample compared to the incident light.

The formula that captures this relationship effectively is A = -log T, where T is the transmittance expressed as a fraction (not in percent). This indicates that as transmittance decreases (less light passes through), absorbance increases. The equation can also be transformed to relate absorbance to percent transmittance (%T) using the conversion that %T = T × 100. Thus, the formula A = 2 - log %T arises from manipulating and converting the transmittance to its percentage form while still adhering to the logarithmic relationship.

Additionally, A = log 1/T can also be interpreted through the lens of these fundamental equations, demonstrating that absorbance can be expressed in terms of transmittance.

All of these equations reflect valid expressions of the relationship between absorbance and percentage transmittance, showing the inherent connections present in spectrophotometric analysis. Hence, the correct response encompasses all of the given formulations since