I need help on these chemistry problems. Cant seem to figure out the solubilities.

Question

A solution of CuSO₄ was prepared and added to a well on a 24-well plastic plate. A piece of metal was placed into the solution. The CuSO₄ solution did not react with the piece of metal that was added to the solution. What could the metal be?

Group of answer choices

Na

Zn

Sn

Cu

not enough information

 

A solution of ZnCl was prepared and added to a well on a 24-well plastic plate. A piece of metal was added to the solution. The ZnCl solution reacted with the piece of metal that was added to the solution. What could the metal be?

Group of answer choices

Al

Zn

Sn

Cu

Not enough information

Answer 1

For the first question, you want to refer to a table of activities of metals, or a table of standard reduction potentials. The solution contains Cu2+ ions, and you need to determine if any of the given metals will replace it.

Na, Zn, Sn are all more active than Cu, so they would all react. Cu is the same so NO RXN with Cu

For the second question, the same approach is required. Consult activity series table or reduction potential table. Zn ions are in solution. Will any of the choices replace Zn?

Al is the only one that is more active than Zn, so it will be the only one to react.