Answer: B

A differential pulse polarographic analysis of a mixture of zinc and cadmium was performed in 0.1MHCl. The peak potential for zinc is at 0.657V and that for cadmium is at 0.548V. When a 0.500ppm zinc standard is analyzed, i is 180.5at 0.657V and 63.5 at 0.548V. A standard solution of 0.621ppm cadmium has a ip of 48.6 at 0.657V and 141.8 at 0.548V. What is the concentration of cadmium in a sample if i7 is 146.0 at a potential of 0.657V and 83.5 at a potential of 0.548V. A. 0.370ppm B. 0.160ppm C. 0.185ppm D. 0.320ppm