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What is the value of the equilibrium constant for the cell reaction below at 25 degree...

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xkat123 | Student, Undergraduate | Honors

Posted July 10, 2013 at 3:24 AM via web

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What is the value of the equilibrium constant for the cell reaction below at 25 degree C? E degree cell = 0.61

2Cr(s) +3Pb^2+(aq) ====> 3Pb(s)+2Cr^3+(aq)

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jerichorayel | College Teacher | (Level 1) Senior Educator

Posted July 10, 2013 at 5:59 AM (Answer #1)

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We can use the expression relating the equilibrium and the delta G: 

`0 = E^o _(cell) - (RT)/(nF) lnK`

`(RT)/(nF) lnK =E^o _(cell)`

 

`lnK = (E^o _(cell) * nF)/(RT) `

 

Where:

`K ` = equilibrium constant

`E^o _(cell)` = is the standard cell potential at the temperature of interest = 0.61

`n` = 6 

`F` = 96485 C/mol

`R` = 8.31447 J/mol-K

`T` = 25 + 273.15 = 298.15 K

 

 

`lnK = (0.61*6*96485)/(8.31447*298.15) `

 

`lnK = 142.453 `

 

`K = e^(142.453) `

`K = 7.35e^61 answer`

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