Which of these ions will spontaneously react with ni (s) in solution? which of these ions will spontaneously react with in solution? cr3 + (aq) ba2 + (aq) pb2 + (aq) li + (aq) ?

Nickel metal will react spontaneously with the aqueous lead solution [Pb2 + (aq) ].

Oxidation is a chemical reaction involving the loss of electrons. In the reactivity series of metals, chromium, barium, and lithium are more reactive or more easily oxidized than nickel.

In the given problem, because nickel is in its elemental (solid metal) form, for it to react with the solution, it will have to be converted into its cationic form (which is positively-charged) by losing electrons. However, if the solution that nickel is reacted with is more easily oxidized compared to nickel, then the reaction will not be spontaneous because nickel is stable in this case.

On the other hand, if nickel is immersed in a solution of a metal which is more stable than it is, such as lead, nickel will be oxidized and lose its electrons to the more stable metal. The more stable metal in solution will accept the lost electrons of nickel and form a solid deposit, while nickel will be in its ionic form in solution.

Below is a reaction between nickel metal and aqueous lead nitrate solution.