The Absorbance of a Solution of Path Length 10 $\quad\quad\quad\quad\quad\quad\varepsilon /\left(10^{5} \mathrm{dm}^{3} \mathrm{~mol}^{-1} \mathrm{~cm}^{-1}\right)$

Multiple Choice

The absorbance of a solution of path length 10.0 cm that contained two cyanine dyes, A and B, was found to be 24.1 ? 10³ at a wavelength of 550 nm and 21.9 ? 10³ at a wavelength of 650 nm. Use the following data for the molar absorption coefficients of the dyes at these wavelengths to determine the concentration of dye A in the solution.
$\quad\quad\quad\quad\quad\quad\varepsilon /\left(10^{5} \mathrm{dm}^{3} \mathrm{~mol}^{-1} \mathrm{~cm}^{-1}\right)$
$\begin{array}{lcc} &\quad\quad 550 \mathrm{~nm} & \quad\quad650 \mathrm{~nm} \\\text { Dye A } & 1.48 & 0.24 \\\text { Dye B } & 0.56 & 2.29\end{array}$

A) 0.008 mol dm^-3
B) 0.020 mol dm^-3
C) 0.015 mol dm^-3
D) 0.025 mol dm^-3