In order to determine the amount of Cd in a sample of Zn metal the following procedure was followed. A 1.00-gram sample
Posted: Tue May 17, 2022 6:11 am
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. 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 μA 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 18.5μA.
Calculate the percent by weight of Cd in the sample Zn sample (Cd
is 112.41g/mol).
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. 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 μA 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 18.5μA.
Calculate the percent by weight of Cd in the sample Zn sample (Cd
is 112.41g/mol).