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

Question

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

i know that the absorbance is .977 but i don't know how to work out A=log (1/T)

Answer 1

A = log (1/T)

Punch in 0.977 on your calculator.
Now take the antilog of 0.977 to obtain 1/T. To do that, hit the 10^x key. The calculator display should read 9.48418. That is 1/T. Then take the reciprocal of that to obtain 0.10544. Multiply that by 100 to obtain 10.544%T. I have used more digits than allowed so you can check your display reading with mine. I hope this helps. I did not check your A value of 0.977. But A = 0.977 is %T of 10.5%.

Answer 2

To calculate the absorbance (A) from the percent transmittance (%T) value, you can use Beer's Law equation:

A = log(1/T)

In this equation, T represents the transmittance, which is measured as a percentage.

To work out A, you need to convert the transmittance value from a percentage to a decimal. You can do this by dividing the percent transmittance value by 100:

T = %T / 100

Once you have the decimal transmittance value (T), you can use the equation to calculate the absorbance (A).

In your case, you mentioned that the percent transmittance (%T) is unknown, so you can't directly calculate the absorbance using the equation. Instead, you need to know the %T value in order to substitute it into the formula.

If you have the absorbance (A) value of 0.977, and you want to find the corresponding percent transmittance (%T), you can rearrange the Beer's Law equation:

A = log(1/T)

To solve for T, you can rewrite the equation as:

1/T = 10^(-A)

Then, isolate T:

T = 1 / (10^(-A)).

Finally, substitute the given A value of 0.977 into the equation:

T = 1 / (10^(-0.977))

Using a calculator, evaluate this expression to find the percent transmittance (%T) value.

Note: The equation A = log(1/T) assumes a linear relationship between absorbance and concentration, as defined by Beer's Law.

help pls

A = log (1/T)

To calculate the absorbance (A) from the percent transmittance (%T) value, you can use Beer's Law equation: