Question

An unknown metal displaces cadmium (Cd) from solution but does not displace chromium (Cr). Using the activity series, determine the unknown metal.

lead (Pb)
manganese (Mn)
iron (Fe)
zinc (Zn)
cobalt (Co)

Answer 1

Answer: iron

Explanation: Plato users

Answer 2

This is the order of activity in decreasing way for the mentioned metals

Mn>Zn>Cr>Fe>Cd>Co>Ni>Pb

Fe is in between Cr and Cd, it is more active than Cd and less active than Cr, so it will displace Cd but not Cr.

Answer:Fe (it will displace Cd, but not Cr)