The standard reduction potentials of Zn ²⁺ | Zn , Cu ²⁺ | Cu and Ag ⁺ Cu and Ag ⁺ Ag are respectively -0.76,0.34 and 0.8 ~V . The following cells were constructed : (1) Zn | Zn ²⁺ | | Cu ²⁺ | Cu (2) Zn | Zn ²⁺ | | Ag ⁺ | Ag (3) Cu | Cu ²⁺ | Ag ⁺ | Ag What is the correct order of E_ cell ^ of these cells?

Step-by-step solution

Given Zn ²⁺ Zn E^ =-0.78 ~V Cu ²⁺ Cu E^ =0.34 ~V Ag ⁺ Ag E^ =0.8 ~V Cell reaction of (1) is Zn + Cu ²⁺ Zn ²⁺+ Cu E_ cell ^ =E_ oxidation +E_ reduction =+0.78+0.34=+1.12 ~V Cell reaction of (2) is Zn + Ag ⁺ Zn ²⁺+ Ag E_ cell ^ =0.78+0.8=+1.58 ~V Cell reaction of (3) is : Cu + Ag ⁺ Cu ²⁺+ Ag E_ cell ^ =-0.34+0.8=+0.46 So, the correct order of E_ cell ^ of these cell is - b > a > c .