[zcabral]

Would the following errors cause an increase or decrease in absorbance and % Transmittance?
A= increase B=decrease
Errors:
1.insoluble particles were accidentally pipetted into the cuvette with the solution...A:? %T:?

2.the cuvette was wet and not prerinsed with the solution.A:? %T:?

3.fingerprints were not wiped off the outside of the cuvette. A:? %T:?

4.the wavelength was changed from max to max +10 nm. A:? %T:?

My answers:
1.A: A    %T: B
2.A:   A  %T: A
3.A:   B  %T: B
4.A:   A  %T: A
    * 1 hour ago
    * - 3 days

[Polleke]

Zcabral,

check this out: http://www.chemicalforums.com/index.php?topic=25662.msg97446#msg97446

I know its not a direct answer to your question, but maybe this may allready help a bit.
Its a discussion about the problems that might occur when measuring with absorbance.

[ARGOS++]

Dear Zcabral;

Polleke is giving you the right Hint, if you follow therein the “Beer-Lambert”-Link!

Have you realised?:

Why is only your first answer different for A: and  %T: ??

You may not believe it, but it’s the only that is correct!

So the best will be to follow the Hint Polleke has given and study how Absorption and %Transmittance are related.
For Question 4 you have also to find out what Lambda_max means!

But one Question remains: What is the meaning of:  1 hour ago & - 3 days ?

I hope we have been of some help to you.

Good Luck!
                    ARGOS⁺⁺