Name: 10. (15 points) In order to determine the amount of Cd in a sample of Zn metal the following procedure was followe

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Name 10 15 Points In Order To Determine The Amount Of Cd In A Sample Of Zn Metal The Following Procedure Was Followe 1 (115.33 KiB) Viewed 88 times

Name: 10. (15 points) In order to determine the amount of Cd in a sample of Zn metal the following procedure was followed. A 1.00-gram sample of the Zn metal is dissolved in 50 mL of HCl and then diluted to 250.00mL. A 25 mL aliquot is transferred to a polarographic cell. The oxygen is purged out of the sample with N2. A polarogram (Hg drop electrode) is recorded in the range of 0 V to -1 V against a standard Ag/AgCl electrode. A “wave” appears at E1/2~-0.65 V with a signal of 7.6 uA being recorded (reduction of Cd2+ to Cd in the Hg amalgam). A 5 mL portion of 5.00 x10-4 M CdCl2 is added to the cell and a second polarogram is recorded. The wave showed the same E1/2, but the signal is increased to 18.5uA. Calculate the percent by weight of Cd in the sample Zn sample (Cd is 112.41g/mol).