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(EXTRA CREDIT - 10 points) Ammonia can be determined spectrophotometrically by its reaction with phenol and hypochlorite (CIO'). A 30.14 mg sample of protein was digested to convert all of the nitrogen present to ammonia. was placed in a 50 ml flask and treated with excess phenol and hypochlorite and diluted to the mark. The absorbance at 625 nm of this solution in a 1.00 cm cuvet was 0.605. A 10 mL portion of standard NHẠCI containing 0.200 mg NH C1 per mL was added to a 50 mL flask, treated with excess phenol and hypochlorite and diluted to the mark as above. The absorbance at 625 nm was 0.502 in a 1.00 cm cuvet. A blank was prepared by adding phenol and hypochlorite reagents to a 50 ml flask and diluting to the mark. The absorbance was 0.114 in a 1.00 cm cuvet at 625 nm. Calculate the percentage by weight of nitrogen in the protein sample. a