An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T values for the diluted aspirin solution prepared by the student is

and , respectively.

The Beer's law plot is usually absorbance (y axis) against concentration (x axis) so the slope is

absorbance (no units)/concentration (mol litre-1)

so the units of the slope are litre mole-1

Thus to find the absorbance of an unknown we need to multiply the concentration of the unknown (0.000630 mole litre -1) by the slope (1550.2 litre mole-1). The units will cancel to give no units which is in reality 'absorbance'.

To find the expected absorbance and %T values for the diluted aspirin solution, we can use the Beer-Lambert Law, which relates the concentration of a solution to its absorbance.

The Beer-Lambert Law is given by the equation: A = εcl, where A is the absorbance, ε is the molar absorptivity (also known as the molar extinction coefficient) in M^-1cm^-1, c is the concentration in M, and l is the path length in cm.

In this case, the unknown concentration of the diluted aspirin solution is given as 0.000630 M.

We are also given that the Beer's Law plot passed through the origin with a slope of 1550.2 M^-1. This slope represents the molar absorptivity (ε) of the compound, which is a measure of how strongly the compound absorbs light at a particular wavelength.

Using the given values, we can calculate the expected absorbance as follows:
A = εcl
A = (1550.2 M^-1)(0.000630 M)(l)

The path length (l) is not provided in the question, so we cannot calculate the exact value of absorbance without it. However, we can still determine the relationship between absorbance and the given values.

To calculate the %T (percent transmittance) value, we can use the formula: %T = 100 - A.

So, the expected %T value would be given by:
%T = 100 - A
%T = 100 - (1550.2 M^-1)(0.000630 M)(l)

Without knowing the path length (l), we cannot calculate the exact values of absorbance and %T. However, the formulas provided above allow us to understand the relationship between these values and the given information.