What happens when Zn metal is dipped in Ni (NO3)2 solution?

Question

What happens when Zn metal is dipped in Ni (NO₃)₂ solution? Can you please explain.

Answer 1

First, we need to know the standard reduction potentials for both Zn and Ni. Or you could look at the activity series of metals to see if Zn is more or less active than Ni.

Looking at the activity series of metals, we find Zn > Ni, so Zn will replace/displace Ni

Zn(s) + Ni(NO₃)₂ ==> Zn(NO₃)₂ + Ni(s)

Ni(s) + Zn(NO₃)₂ ==> NO REACTION

If you look at a table of standard reduction potentials, you find...

Zn²⁺ + 2e- ==> Zn(s) Eº = -0.76 V

Ni²⁺ + 2e- ==> Ni(s) Eº = - 0.25 V

This tells us that Ni²⁺ is easier to reduce/more difficult to oxidize and so is less reactive