Question

The absorbance of an equilibrium mixture containing FeSCN2 was measured at 447 nm and found to be 0.347. What is the equilibrium concentration of FeSCN2

Answer 1

Answer:

The concentration is $C = 1.11 mol/L$

Explanation:

From the question we are told that

     The absorbance is  $A = 0.347$

       The length is  $l = 447 nm = 447 *10^{-7} \ cm$

     

Generally absorbance is mathematically represented as

        $A = \epsilon* C * l$

where $\epsilon$ is the molar absorptivity of  FeSCN2  with a value $\epsilon = 7.0*10^3 L/cm/mol$

 and  $C$ is the equilibrium concentration of FeSCN2

So  

       $C = \frac{A}{\epsilon * l }$

substituting values

        $C = \frac{0.347}{7.0*10^{3} * 447 *10^{-7} }$

         $C = 1.11 mol/L$