Answer:
2.67 × 10⁵ cm⁻¹ M⁻¹
Explanation:
We can relate the absorbance of a solution (A) with the concentration of the analyte (c) using Beer-Lambert law.
A = ε × l × c
where,
ε: molar absorptivity of the vitamin
l: the optical path length
A = ε × l × c
ε = A / l × c
ε = 0.165 / 1.00 cm × 6.18 × 10⁻⁷ M
ε = 2.67 × 10⁵ cm⁻¹ M⁻¹