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## Homework Statement

Calculate the diffusion coefficient (cm2/s) of ferricyanide if cyclic voltammograms conducted on a solution of 1 mM KClO4 + 5 mM K4Fe(CN)6 at scan rates of 1, 2, 5, 10, 20, and 50 mV/s, resulted in peak currents of 76, 100, 175, 243, 348 and 552 mA. The electrode used for the experiment had been modified with a polymeric coating an effective area of 0.56 cm

^{2}.

## Homework Equations

i

_{pc}=(269000)n

^{3/2}AD

^{1/2}C v

^{1/2}

A=0.56 cm

^{2}

n=1

C= 0.000005 mol/cm

^{3}

## The Attempt at a Solution

I ploted the i

_{pc}vs. v

^{1/2 }and found the slope of the line which was approx. 76.747

i

_{pc}/v

^{1/2}= 76.747

Isolating for D =[76.747/((269000)n

^{3/2}AC)]

^{2}

=[76.747/((269000)1

^{3/2}0.56x0.000005)]

^{2}

= 10 382.51

which is clearly wrong since the theoretical value of D is 7.6 x 10

^{-6}

Can anyone point out my mistake? I have a feeling it's with the concentration though I'm not quite sure...