A 25.0-mL aliquot of an aqueous quinine solution was diluted to 50.0 mL and found to have an absorbance of 0.656 at 348 nm when measured in a 2.50-cm cell. A second 25.0-mL aliquot was mixed with 10.00 mL of a solution containing 25.7 ppm of quinine; after dilution to 50.0 mL, this solution had an absorbance of 0.976 (2.50-cm cell). Calculate the concentration of quinine in parts per million in the sample.

The  value  is  

Explanation:

From the question we are told that

 The volume of the first  aliquot is

 The  volume after dilution is  

 The  Absorbance of the first solution  is  

 The  wavelength at which the absorbance occurred is  

    The  length of the cell

    The volume the second  aliquot is

     The  volume of the solution it was mixed with is  

     The  concentration of quinine in the 10 mL solution  

    The volume of the second solution after dilution is

      The  absorbance of the second solution is

Generally the concentration of quinine is mathematically represented as

=>    

=>  

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