Answer:
3.00 cm
Explanation:
The absorbance can be expressed using Beer-Lambert's law:
A = ε*b*c
Where ε is a constant for each compound, b is the optical path, and c is the molar concentration of the compound.
Now we match the absorbance values for both solutions, because we want the absorbance value to be the same for both solutions:
A = ε * 1.00 cm * 7.68x10⁻⁶M = ε * b * 2.56x10⁻⁶ M
And solve for b:
ε * 1.00 cm * 7.68x10⁻⁶M = ε * b * 2.56x10⁻⁶ M
1.00 cm * 7.68x10⁻⁶M = b * 2.56x10⁻⁶ M
b = 3.00 cm
