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A 0.2257g sample of standard steel contains 0.95% or 2.14ppm (1 mg L​-1) manganese. The sample...

A 0.2257g sample of standard steel contains 0.95% or 2.14ppm (1 mg L​-1) manganese. The sample is then diluted 3 times giving 1.07ppm, 0.535ppm, and 0.268ppm. Each sample's absorbance was then read using a spectrophotometer were 0.951, 0.491, 0.258, 0.136, respectively. Determine the amount of manganese (in parts per million) of an unknown sample if the absorbance was read to be 0.510.

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Expert Solution

firstly a callibration curve has to be made using absorption values of samples of known concentration.Then the concentration of unknown sample can be determined from the callibration curve-

data

         concentration(ppm)                                                   Absorbance

           2.14                                                                      0.951

           1.07                                                                       0.491

           0.535                                                                     0.258

          0.268                                                                      0.136

          unknown                                                                  0.510

ans=0.717ppm

queen_honey_blossom answered 2 years ago
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