A chemist wants to make 450. mL of a solution that is 0.500 M in concentration of Zn2+. Her available materials are 1.45 M ZnSO4 and 0.200 M ZnCl2. Unfortunately for the chemist, there is no deionized water available to dilute the solutions. Assuming that the solutions’ volumes are additive, how many mL of each solution are required to make the 450. mL of 0.500 M Zn2+solution? Which of the ions present has the lowest concentration in the final solution? Volume of 1.45 M ZnSO4 Volume of 0.200 M ZnCl2 Ion with lowest concentration in final solution

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.