Why Na & K are Not Acceptable for Reducing PbCl2

[Faiq]

Homework Statement

A question asked to write an equation for the reduction of PbCl2

The answer key was
PbCl2+X ----> Pb+XCl2
where X can be: ...Fe, Mg...but not Na or K

Why are Na or K not acceptable?

 

[John Park]

Cost could be one reason. And which would you rather work with: sodium / potassium vs. iron / magnesium?

 

[Ygggdrasil]

Based on the activity series, all of those metals should be able to displace Pb2+ in a single displacement reaction. Maybe it just has to do with the fact that FeCl2 and MgCl2 are valid formula but NaCl2 and KCl2 are not (rather the equation would be PbCl2 + 2Na --> Pb + 2NaCl).

 

[Faiq]

Based on the activity series, all of those metals should be able to displace Pb2+ in a single displacement reaction. Maybe it just has to do with the fact that FeCl2 and MgCl2 are valid formula but NaCl2 and KCl2 are not (rather the equation would be PbCl2 + 2Na --> Pb + 2NaCl).

The question doesn't make any such type of recommendation though