Two species, A and B, are separated on a 2.00 m long column which has 5.000 x 103 plates when the flow rate is 15.0 mL/min. A species that is non-absorbing and known not to interact with the stationary phase, elutes in 30.0 s. Compound A elutes from the column in 5.00 min and Compound B elutes in 12.00 min.calculate the peak widths (in seconds) for Compounds A and B,

Respuesta :

Explanation:

The given data is as follows.

         [tex]t_{m}[/tex] = 30.0 sec,     [tex]t_{r1}[/tex] = 5 min = [tex]5 \times 60 sec[/tex] = 300 sec

         [tex]t_{r2}[/tex] = 12.0 min = [tex]12 \times 60 sec[/tex] = 720 sec

Formula for adjusted retention time is as follows.

      [tex]t'_{r} = t_{r} - t_{m}[/tex]

                 = 300 sec - 30.0 sec

                 = 270 sec

   [tex]t'_{r2}[/tex] = 720 sec - 30 sec

                            = 690 sec

Formula for relative retention ([tex]\alpha[/tex]) is as follows.

          [tex]\alpha = \frac{t'_{r2}}{t'_{r1}}[/tex]

                     = [tex]\frac{690 sec}{270 sec}[/tex]

                     = 2.56

Thus, we can conclude that the relative retention is 2.56.