KCET2019ChemistryElectrochemistry
Given: ( E_ M n⁺⁷ ⁰ M n⁺²=1.5 ~V ) and ( E_ M n⁺⁴ ⁰ M n⁺²=1.2 ~V ), then ( E_ M n⁺⁷ ⁰ M n⁺⁴ ) is
Options
- A( 1.7 ~V )
- B( 2.1 ~V )
- C( 0.3 ~V )
- D( 0.1 ~V )
Correct answer
A. ( 1.7 ~V )
Step-by-step solution
(A) M n⁺⁷+5 e⁻ M n²⁺ G⁰=-n FE ⁰ G ⁰=-5 ~F 1.5M n⁺⁴+2 e⁻ M n²⁺ G ⁰=-2 ~F 1.2 Required equation M n⁺⁷+3 e⁻ M n⁴⁺ G ⁰=-3 FE ⁰ -3 FE ⁰=-7.5 ~F +2.4 ~F E ⁰=1.7 ~V