Karnataka Board PUCPUC Science 2nd PUC Class 12

Using the E° Values of a and B, Predict Which is Better for Coating the Surface of Iron E°(Fe+2/Fe) = -0.44v to P - Chemistry

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Numerical

Using the E° values of A and B, predict which is better for coating the surface of iron [E°(Fe+2/Fe) = -0.44V] to prevent corrosion and why?

Given: E° (A+2/A)=-2.37 V: E°(B+2/B)= -0.14V

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Solution

 

Given:

E°(A+2 / A) = 2.37 V

E°(B+2 / B) = -0.14 V

`E_(cell)=E_(cell)^@ - (0.0591)/n log  [Cr^(3+)]^2/[Fe^(2+)]^3`
                                                                     (Nernst Equation)
`0.261 = E_(cell)^@ = 0.0591/6 log  [0.001]^2/[0.001]^3`

`0.261 = E_(cell)^@ - (0.591 xx 2)/6`

`E_(cell)^@ = 0.2807V`

 

 

 

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2015-2016 (March) All India Set 2 C

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