Question

The molar absorptivity of Beta-carotene at 490 nm is 1.36 x 105 M-1cm-1. What is the concentration of a solution of Beta-carotene that has an absorbance, A490 = 140 in a cell with a path length of 1 cm? The molar absorptivity of Beta-carotene at 490 nm is 1.36 x 105 M-1cm-1. What is the concentration of a solution of Beta-carotene that has an absorbance, A490 = 140 in a cell with a path length of 1 cm? 2.5 x 10-4 M 5.0 x 10-4 M 1.3 x 10-4 M 2.0 x 10-3 M 1.0 x 10-3 M?

Answer 1

Answer:

The correct answer to the following question will be Option E (1.0 x 10⁻³ M).

Explanation:

The given values are:

$A\lambda =140$

$\varepsilon=1.36\times 10^5 \ M \ {cm^{-1}}$

L = 1 \ cm

As we know,

⇒  $A\lambda=\varepsilon CL$

On putting the given values in the above formula, we get

⇒  $140=1.36\times 10^5\times C\times 1$

⇒  $C=\frac{140}{1.36\times 10^5}$

⇒  $C=102.9\times 10^{-5} \ M$

So that option E is the right answer.