[Galiligp]

hello;
I'm a student and I'm taking a "general chemistry" course. in the last lab meeting i had - i used spectroscope to find the Absorbency of orange methyl indicator in different wave length. (500; 510; 520;530) and in differents materials (acid; base; pH=3; pH=4) and i got 4 results in each substance(in a chart like form). now I'm asked to find the pka using :
pka = ph - A-A1/A2-A.
but i dont understand what numbers i need to put as A; A1 ; A2. i know that A is the negative log of T but still i dont understand it. i tried to find info on the beer Lambert law but all the info i found doesn't connect to chemistry only to physics and the formula look different.

thanks you all in advance and I'm sorry for my level of English

Nir.

[Galiligp]

hello again
i wonder if i'v done anything wrong with my post and as a result no one answer it?
do you need more info?

thanks again

nir

[Ligander]

i know that A is the negative log of T but still i dont understand it.

Nir.

 What is T ? Are you Israeli Nir?
 

[Galiligp]

yes i am.
I manege to figure it out and i want to write the answer and maybe it will help someone someday.

T is transmittance.
all i had to do is to take the acid and base number and insert them as A1 for acid and A2 for base then the A will be the numbers from the PH 3 and PH 4 test tubes.
that gave me the pKa.