Question

Which of the following redox reactions do you expect to occur spontaneously in the forward direction?

Check all that apply.

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)
Al(s)+3Ag+(aq)→Al3+(aq)+3Ag(s)
Ni(s)+Zn2+(aq)→Ni2+(aq)+Zn(s)
Fe2+(aq)+Cd(s)→Fe(s)+Cd2+(aq)

Answer 1

Among the choices provide above the redox reactions do you expect to occur spontaneously in the forward direction is the below:

Fe2+(aq) + Zn(s) -> Fe(s) + Zn2+(aq)
Al(s) + 3Ag+(aq) -> Al3+(aq) + 3Ag(s)

Those reactions will proceed when the metal that is a solid is higher up in the electromotive series than the metal that is an ion (dissolved).

Answer 2

Answer: The correct answer is Option 1 and Option 2.

Step-by-step explanation:

Redox reactions are termed as the reactions in which reduction and oxidation reactions occur simultaneously.

Reduction reactions are the ones where a substance gains electrons. The oxidation state of the substance gets reduced.

Oxidation reactions are the ones where a substance looses electrons. The oxidation state of the substance is increased.

All the given reactions are a type of single displacement reactions. In this, a more reactive metal displaces a less reactive metal from its chemical reaction. The reactivity is determined from a series known as reactivity series. A metal which lies above in the series is more reactive than the metals which lie below in the series.

`A+BC\rightarrow AC+B`

From the given options:

Option 1:
`Ni(s)+Pb^(2+)(aq.)\rightarrow Ni^(2+)(aq.)+Pb(s)`

Here, nickel lies above in the series than lead. Thus, it will easily replace lead from its chemical reaction.

Option 2:
`Al(s)+3Ag^+(aq.)\rightarrow Al^(3+)(aq.)+3Ag(s)`

Here, aluminium lies above in the series than silver. Thus, it will easily replace silver from its chemical reaction.

Option 3:
`Ni(s)+Zn^(2+)(aq.)\rightarrow Ni^(2+)(aq.)+Zn(s)`

Here, nickel lies below in the series than zinc. Thus, it will not easily replace zinc from its chemical reaction.

Option 4:
`Fe^(2+)(aq.)+Cd(s)\rightarrow Fe(s)+Cd^(2+)(aq.)`

Here, cadmium lies below in the series than iron. Thus, it will not easily replace iron from its chemical reaction.

Thus, the correct answer is Option 1 and Option 2.