Calculating stray light as percentage of incident light

[atomicblast]

Hi, I've a chem assignment in which I've to calculate the stray light, Ps as a percentage of the incident light, Po.

Given the apparent absorbance A(app) 0.047, concentration of the solution 2.00 x 10pwr-6, cell length of 1cm, activity coefficients = 1.

I calculated the transmittance to be A = -log T , where T = 0.8974

T = P + Ps / Po + Ps = 0.8974
T = P / Po = 0.8974

I'm stuck after that with 2 unknowns in the equation. Could someone advice me on this?

Thanks a lot!

 

[Gokul43201]

It would help (yourself) a great deal if you could describe the experiment involved.

 

[atomicblast]

Okie, this is the question given:

The apparent absorbance of a solution of a weak acid, HA, was measured at different pH values (you may assume the pH meter was correctly calibrated, that activity coefficients are unity throughout, and that concentrations are reliable. A 1.00cm cell was used. None of the buffers used absorbs at the wavelength used. Results were as follows:

Concentration, M - 2.00 x 10pwr-6

Apparent Absorbance:
0.047 at pH 2,
0.045 at pH 4,
0.018 at pH 6,
0.010 at pH 8,
0.009 at pH 10

1) Calculate the stray light, Ps, as a percentage of the incident light, Po, in the spectrophotometer used.


Thanks again!