Determine the molar absorptivity of the acidic form of bromo

Determine the molar absorptivity of the acidic form of bromocresol green at 445 nm and at 615 nm.

Stock solution of bromoscresol green contains 80.0 mg/L

Molar mass of bromocresol green is 698.0 g/mol

*This was done in a lab so I\'ll put down some information if needed:

10mL of bromocresol green was mixed with 40mL of .4M HCl

10mL of bromocresol green was mixed with 40mL of .4M NaOH

Here are the absorbances at 445nm:

.4M HCl plus the bromocresol green= .382A

.4M NaOH plus the bromocresol green= .045A

Here are the absorbances at 615nm:

.4M HCl plus the bromocresol green= .003A

.4M NaOH plus the bromocresol green= .872A

10 ml bromocresol contains = (10/1000) x 80/L = 0.8 mg = 8x10^ -4 gm,

moles = 8x10^ -4 /689 = 1.16 x10^ -6

when 10 ml bromocresol mixed with 40 ml HCl , total vol = 50 ml =0.05 liter

cocn = ( 1.16x10^ -6 )/(0.05) = 2.3 x10^ -5 M

at 445 nm

when HCl added A= 0.382 = e (2.3x10^ -5) , e = 16608.7 M-1cm-1

when NaOH added A= 0.045= (2.3x10^ -5) , e = 1956.5 M-1cm-1,

at 615 nm

when HCl added A= 0.03= e(2.3x10^ -5) , e = 1304.35 M-1cm-1,

when NaOh is added A= 0.872 = e(2.3x10^ -5) , e = 37913 M-1cm-1