Answer:
See explaination
Explanation:
The rate of the electrochemical reaction per unit area is given by
r=\frac{i}{nFA}
where r is the Reaction Rate (in mol s-1 cm-2)
i is the Current Generated (in A)
n is the Number of moles of electrons per mole of reactant
F is Faraday's Constant= 96,500 C mol-1
A is the Electrode Area (in cm2)
(Unit of current should be expressed in terms of Columb per second, C s-1 to obtain reaction rate in mol s-1 cm-2)
Net Reaction Rate for Reaction A:
Given: Number of moles of A, n=2 moles
Current generated, i=5 A=5 C s-1
Electrode Area, A= 2cm2
Thus reaction rate is
\mathbf{r=\frac{5 C s^{-1}}{2*96500 C mol^{-1} *2 cm^{2}}= 1.3*10^{-5} mol s^{-1} cm^{-2}}
Net Reaction Rate for Reaction B:
Given: Number of moles of B, n=3 moles
Current generated, i=15 A=15 C s-1
Electrode Area, A= 5cm2
Thus reaction rate is
\mathbf{r=\frac{15 C s^{-1}}{3*96500 C mol^{-1}*5cm^{2}}= 1.036*10^{-5} mol s^{-1} cm^{-2}}
Reaction A has higher net reaction rate.
