Which of the following statements is true? a. Ag (s) reacts spontaneously with 1 M H + (aq). b. Ag (s) reacts spontaneously with Ni2+. c. Ag (s) reacts spontaneously with 1 M NO3 - in 1 M H + (aq). d. Ni2 + reacts spontaneously with 1 M H + (aq) to form H2. e. Ni2 + reacts spontaneously with H2 (g).

Correct answer is a. Ag (s) reacts spontaneously with 1M H + (aq).

Explanation:

A charasteristic of metals is that they lose easily electrons, cations tends to gain electrons to react and anions tends to lose or share electrons to react.

If you want to make a chemical reaction you must to mix a reagent that tends to lose electrons with other that tends to gain them.

In the statement (a) we have a metal that loses electrons and a cation that can obtain them, so is the right answer.

note that the other optios have:

b) Metal with metal cation, not react beacause left a medium of reaction.

c) Both loses electrons

d) Both tends to gain electrons.