Question

If `E_(A^(+2)//A)^(@)=-0.30 V and E_(A^(+3)//A^(+2))^(@)=0.40 V,` the standard Emf of the reaction: `A+2A^(+3)to3A^(+2)` will be :-
A. 0.30 V
B. 0. 40 V
C. 0. 70 V
D. 0. 10 V

Answer 1

Correct Answer - C
Anode reaction `AtoA^(+2)+2e^(-)`
cathode reaction `2A^(+3)+2e^(-)to2A^(+2)`
`E_(ceel)^(@)=E_(cathode)^(@)-E_(Anode)^(@)`
`=0.4-(-0.3)`
0.7 V