Question

Based on the standard potential values, determine which reaction is taking place?Write the reaction equation!

(Cu2+ and Fe,) (Fe2+ and Cu, )(I2 and Br-), (Br2 and I-,)( Cu+HCl, )(Fe + HCl, )(K+H20,)(Ni+H20,)

The ‘ and ‘ meaning ‘+ ‘

Answer 1

These reactions are possible if sum of oxidation and reduction potential is greater than 0.
The reduction potential of Cu²+ is 0.34 and oxidation potential of Fe to Fe²+ is 0.41 so first reaction is possible.
Second reaction is not possible since reduction potential of Fe²+ to Fe is -0.41 and oxidation potential of Cu to Cu²+ is -0.34.

The third reaction is not possible because the oxidation potential of Br- to Br2 is -1.07 and reduction potential of I2 to l- is 0.54.Net reaction potential is less than 0.

Fourth is possible as it is reverse reaction of third.

Fifth reaction is not possible as oxidation potential of Cu to Cu+ is -0.52- and reduction potential of H+ is 0.

Sixth reaction is possible since oxidation potential of Fe to Fe2+ is 0.41 and H+ to H is zero.
Seventh reaction is highly feasible as oxidation potential of K to K+ is -2.92 and H+ to H is 0.

The last reaction is possible as oxidation potential of Ni to Ni²+ is 0.23 and reduction potential of H+ is 0.

P.S.You do not need to remember the reduction potential values,you only need to remember the electrochemical series.the elements which are placed higher replace the elements below them from their compounds.

All the best.