Question

A blank solution containing only solvent had an absorbance of 0.029 at the same wavelength. Find the molar absorptivity of compound A.

Answer 1

The question is incomplete. Searching in google I found: A 3.96x10⁻⁴ M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvette. A blank solution containing only solvent had an absorbance of 0.029 at the same wavelength. Find the molar absorptivity of compound A.

The molar absorptivity of compound A is 1502.5 M⁻¹cm⁻¹.

Step-by-step explanation:

The question is incomplete. Searching in google I found: A 3.96x10⁻⁴ M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvette. A blank solution containing only solvent had an absorbance of 0.029 at the same wavelength. Find the molar absorptivity of compound A.

The absorbance (A) is given by:

`A = \epsilon cl`

Where:

c: is the concentration of compound A = 3.96x10⁻⁴ M

ε: is the molar absorptivity of compound A =?

l: is the pathlength = 1 cm

`A_(s)`: is the absorbance of the solution= 0.624

`A_(b)`: is the absorbance of the blank solution= 0.029

First, we need to find the absorbance of compound A:

`A = A_(s) - A_(b) = 0.624 - 0.029 = 0.595`

Now, we can calculate the molar absorptivity of compound A:

`\epsilon = (A)/(cl) = (0.595)/(3.96 \cdot 10^(-4) M*1 cm) = 1502.5 M^(-1)cm^(-1)`

Therefore, the molar absorptivity of compound A is 1502.5 M⁻¹cm⁻¹.

I hope it helps you!