Question

The complex [FeSCN]2+ has an absorptivity of 6.14×10−2 L/(mg⋅cm) at a wavelength of 580 nm. The transmittance of a solution sample was measured in a 1.00 cm cell, and the percent transmittance %T was 53.9%. Calculate the concentration of the solution in ppm.

Answer 1

Answer:

4.36 ppm

Explanation:

First we convert percent transmittance to absorbance:

• A = 2 - log(%T)

• A = 0.268

Then we calculate the concentration of the solution, using Lambert-Beer's equation:

• A = ε*l*C

It is usually used with molar concentrations but given that the given absortivity is in ppm terms and the answer is also in ppm, we can simply use the given value.

• 0.268 = 6.14x10⁻²L·ppm⁻¹ * 1.00 cm * C

• C = 4.36 ppm

Answer 2

The concentration of the solution is 4.36 ppm when the percent transmittance measured in a 1.00 cm cell is 53.9%, the absorptivity is 6.14x10⁻² L/(mg*cm), and the wavelength is 580 nm.        

 

We can calculate the concentration of the solution with the Beer-Lambert equation:  

$A= \epsilon Cl$   (1)  

Where:

• A: is the absorbance

• C: is the concentration =?

• l: is the length of the optical path = 1.00 cm  

• ε: is the absorption coefficient = 6.14x10⁻² L/(mg*cm)  

With the transmittance, we can find the absorbance as follows:

$A = -log T$  

Where T is the transmittance = 53.9% = 0.539

So, the absorbance is:

$A = -log T = -log(0.539) = 0.268$

Finally, by solving equation (1) for C, we have:

$C = \frac{A}{\epsilon l} = \frac{0.268}{6.14 \cdot 10^{-2} L/(mg*cm)*1.00 cm} = 4.36 mg/L$

Therefore, the concentration of the solution is 4.36 ppm.

You can find more about absorbance and transmittance here:

• brainly.com/question/14919298

• brainly.com/question/6167291

I hope it helps you!