Question 1

Consider the following mechanism. 
 $$\begin{array} { l } 
M \rightarrow M _ { a ds } ^ { + } + e ^ { - } \
\
M _ { a d s } ^ { + } \rightarrow M _ { a d i } ^ { 2 + } + e ^ { - } \
\
M _ { a d s} ^ { + } \rightarrow M _ { s o l } ^ { 2 + }
\end{array}$$ 
 The faradaic impedance of this system is to be modeled using the Maxwell type circuit with resistances and capacitances. Apart from polarization resistance, how many Maxwell pairs are necessary to adequately model an impedance spectrum from this system? ________
At how many potentials should EIS be acquired to eliminate the possibility of an infinite number of solutions _________

Accepted Answer

The answer of Consider the following mechanism. 
 \[\begin{array} {...

Question 2

A Frumkin isotherm model will reduce to Langmuir isotherm when parameter "g" is _____

Accepted Answer

The answer of A Frumkin isotherm model will reduce to...

Question 3

Temkin model describes the relationship between _______ and fractional surface coverage
A) rate constant
B) equilibrium constant
C) potential
D) current

Accepted Answer

The answer of Temkin model describes the relationship between _______...

Question 4

Consider the reaction $$\left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] ^ { 4 - } \underset { k _ { - 1 } } { \longleftarrow } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] ^ { 3 - } + e ^ { - }$$ 
 The net reaction rate is given by
A) $$k _ { 1 } \left[ F e ^ { 2 + } \right]$$
B) $$k _ { 1 } \left[ F e ^ { 2 + } \right] - k _ { - 1 } \left[ F e ^ { 3 + } \right]$$
C) $$k _ { 1 } \left[ F e ^ { 2 + } \right] + k _ { - 1 } \left[ F e ^ { 3 + } \right]$$
D) none of the above

Accepted Answer

The net reaction rate is the difference between the forward and reverse reaction rates. The forward reaction rate is given by k1[Fe2+], and the reverse reaction rate is given by k-1[Fe3+]. Therefore, the net reaction rate is given by k1[Fe2+] - k-1[Fe3+].

Question 5

The following impedance spectrum was obtained for an electrochemical system.
 Which of the following mechanisms can be considered to describe the electrochemical system?
A) $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { a ds } ^ { + } + e ^ { - } \
\
M _ { a ds } ^ { + } + M \stackrel { k _ { 2 } } { \longrightarrow } M _ { a ds } ^ { + } + M _ { s o l } ^ { 2 + } + 2 e ^ { - }
\end{array}$$
B) $$\begin{array} { l } 
M \stackrel { x _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M + M _ { a d s } ^ { + } \stackrel { k _ { 2 } } { \longrightarrow } M _ { s d } ^ { 2 + } + M + e ^ { - }
\end{array}$$
C) $$\begin{array} { l } 
M \stackrel { k } { \longrightarrow } M _ { a ds} ^ { + } + e ^ { - } \
\
M _ { ads } ^ { + } \stackrel { k _ { 3 } } { \longrightarrow } M _ { ad s } ^ { 2 + } + e ^ { - } \
\
M _ { ads } ^ { 2 + }  \stackrel { k _ { 3 } } { \longrightarrow } M _ { s o l } ^ { 2 + }
\end{array}$$
D) $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { a ds} ^ { + } + e ^ { - } \
\
M _ { a ds } ^ { + } \stackrel { k _ { 3 } } { \longrightarrow } M _ { s o l } ^ { 2 + } + e ^ { - } \
\
M \stackrel { k _ { 3 } } { \longrightarrow } M _ { so l } ^ { 2 + } + 2 e ^ { - }
\end{array}$$

Accepted Answer

The impedance spectrum shows a depressed semicircle at high frequencies followed by a diffusion-controlled straight line at lower frequencies. This is indicative of a system where charge transfer across the electrode/solution interface is followed by diffusion of the reactants or products in solution. Choice C involves a reversible redox reaction followed by diffusion, which is consistent with the observed spectrum. Choice A involves a charge transfer followed by a chemical reaction, which would result in a different shape of the impedance spectrum. Choice B involves a charge transfer followed by adsorption, which also would result in a different shape of the impedance spectrum. Choice D involves an adsorption followed by a chemical reaction, which again would result in a different shape of the impedance spectrum.

Question 6

A unique method of representing impedance spectrum is
A) Voigt representation
B) Maxwell representation
C) Ladder representation
D) Zero-pole representation

Accepted Answer

Zero-pole representation is a unique method of representing impedance spectrum as it decomposes the spectrum into simple building blocks of poles and zeros. This representation is especially useful for analyzing the frequency response of electrochemical systems.

Question 7

Consider the following elementary reaction $$M \underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }M _ { s ol } ^ { 2 + } + 2 e ^ { - }$$
 
 where M is metal and 
 $$M _ { \text {sol } } ^ { 2 + }$$ 
is metal ion in solution, F denotes Faraday constant. The net faradaic current density due to metal dissolution is
A) $$2 F \left( k _ { 1 } \left[ M _ { s d } ^ { + } \right] - k _ { - 1 } \right)$$
B) $$2 F \left\{ k _ { 1 } - k _ { - 1 } \left[  M _ { s o l } ^ { 2 + } \right] \right\}$$
C) $$F \left\{ k _ { 1 } - k _ { - 1 } \left[ M _ { s o l } ^ { 2 + } \right] \right\}$$
D) $$2 F \left\{ k _ { 1 } + k _ { - 1 } \left[ M _ { s o l } ^ { 2 + } \right] \right\}$$

Accepted Answer

The net faradaic current density for the dissolution of metal M into $M_{sol}^{2+}$ and 2 electrons involves the rate of the forward reaction (metal dissolution) minus the rate of the backward reaction (metal deposition). The forward reaction rate is proportional to the rate constant $k_1$ and the backward reaction rate is proportional to the rate constant $k_{-1}$ and the concentration of $M_{sol}^{2+}$. Since 2 electrons are involved in the reaction, the current density is multiplied by $2F$, where $F$ is the Faraday constant. Therefore, the correct expression is $2F\{k_1 - k_{-1}[M_{sol}^{2+}]\}$.

Question 8

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-In standard notation, the fractional surface coverage ($\theta$ ) of the adsorbed intermediate $$M _ { a ds } ^ { + }$$ 
is given by
A) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } ( 1 - \theta ) - k _ { 2 } \theta - k _ { - 2 } C _ { M _ { a d } ^ { 2 + } }$$
B) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } ( 1 - \theta ) - k _ { 2 } \theta + k _ { - 2 } C _ { M _ { sol } ^ { +2} } ( 1 - \theta )$$
C) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } ( 1 - \theta ) - k _ { 2 } \theta$$
D) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } ( 1 - \theta ) - k _ { - 2 } C _ {M_ {sol } ^ { + 2 } }$$

Accepted Answer

The correct expression for the rate of change of fractional surface coverage ($\frac{d\theta}{dt}$) includes terms for the adsorption of $M$ to form $M_{ads}^+$ which is proportional to the available surface ($1-\theta$), the conversion of $M_{ads}^+$ to $M_{sol}^{2+}$ which reduces the coverage ($-k_2\theta$), and the reverse reaction where $M_{sol}^{2+}$ is converted back to $M_{ads}^+$ which increases the coverage ($+k_{-2}C_{M_{sol}^{+2}}(1-\theta)$).

Question 9

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-In the same mechanism, the steady-state fractional surface coverage of the intermediate is given by
A) $$\theta _ { s s } = \frac { k _ { 1 \dot { dc } } } { k _ { 1 \dot {dc } } + k _ { 2 dc } }$$
B) $$\theta _ { s s } = \frac { k _ { 1 \dot {dc } } } { k _ { \mathrm { dc } } + k _ { 2 \dot { dc } } + k _ { - 2 \dot {dc } } }$$
C) $$\theta _ { s s } = \frac { k _ { 1dc } + k _ { - 2dc } C _ { M _ { sol} ^ {+2} } } { k _ { 1dc } + k _ { 2 dc } + k _ {- 2 dc} C _ { M _ {sol} ^ { +2  }} }$$
D) $$\theta _ { s s } = \frac { k _ { 1dc } - k _ { - 2dc} C _ { M _ { s ol } ^ { +2 } } } { k _ { 1 dc} + k _ { 2dc} + k _ { - 2dc } C _ { M _ {sol} ^ { +2 } } }$$

Accepted Answer

The correct expression for the steady-state fractional surface coverage ($\theta_{ss}$) in a reaction mechanism involving adsorption, desorption, and further reaction steps typically accounts for the rates of these processes. The given expression in choice C correctly incorporates the rates of adsorption ($k_{1dc}$), desorption ($k_{-2dc} C_{M_{sol}^{+2}}$), and further reaction ($k_{2dc}$) to calculate the fractional surface coverage. It balances the forward adsorption and the combined effects of desorption and further reaction of the adsorbed species, considering the concentration of $M_{sol}^{+2}$ in the desorption term.

Question 10

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-In the same mechanism, the faradaic current is given by
A) $$i _ { F } = F \left[ k _ { 1 } ( 1 - \theta ) \right]$$
B) $$i _ { F } = F \left[ k _ { 1 } ( 1 - \theta ) + k _ { 2 } \theta - k _ { - 2 } ( 1 - \theta ) C _ { M _ { \mathbf { sol} } ^ { +2 } } \right]$$
C) $$i _ { F } = F \left[ k _ { 1 } ( 1 - \theta ) - k _ { 2 } \theta + k _ { - 2 } ( 1 - \theta ) C _ { M _ { \mathbf { sol } } ^ { +2 } } \right]$$
D) $$i _ { F } = F \left[ k _ { 1 } ( 1 - \theta ) + k _ { 2 } \theta + k _ { - 2 } ( 1 - \theta ) C _ { M _ { sol} ^ {{ +2 } } } \right]$$

Accepted Answer

The faradaic current, $i_F$, is proportional to the rate of the electrochemical reaction. The correct expression must account for the forward reaction rates ($k_1$ and $k_2$) and the backward reaction rate ($k_{-2}$), considering the surface coverage ($\theta$) and the concentration of $M_{sol}^{2+}$. Option B correctly combines these factors: $k_1(1-\theta)$ for the adsorption of $M$ (unoccupied sites), $k_2\theta$ for the formation of $M_{sol}^{2+}$ from $M_{ads}^+$, and $-k_{-2}(1-\theta)C_{M_{sol}^{+2}}$ for the reverse reaction, considering the concentration of $M_{sol}^{2+}$ and the availability of unoccupied sites ($1-\theta$).

Question 11

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-In the same mechanism, the value of $$\frac { d \theta } { d E }$$ 
is given by
A) $ \frac {(b_{1}k_{1dc}(1-\theta _ { s s })-{b_{2}k_{2dc}}\theta _ { s s } +b_{-2}{k_{-2dc}C_{M^{+2}_{sol}}(1-\theta _ { s s })}}{k_{1dc}+k_{2dc}+{k_{-2d}C_{M^{+2}_{sol}}+{j??}}}$
B) $$\frac { \left( b _ { 1 } k _ { 1 dc} \left( 1 - \theta _ { s s } \right) - b _ { 2 } k _ { 2{ dc } } \theta _ { ss } \right) } { \left( k _ { 1 { dc } } + k _ { 2 dc } + k _ { - 2 dc } C _ {M _ { s ol {  } } ^ { +2 } } + j \omega \Gamma \right) }$$
C) $\frac{\left(b_{1} k_{1dc}\left(1-\theta_{s s}\right)-b_{2} k_{2{dc}} \theta_{ss}+b_{-2} k_{-2 {dc}} C_{M_{sol}^{+2}}\right)}{\left(k_{1 {dc}}+k_{2{dc}}+k_{-2 {dc}} C_{M_{{ sol}}^{+2}}+j \omega \Gamma\right)}$

D) $ \frac {(b_{1}k_{1dc}(1-\theta _ { s s })+{b_{2}k_{2dc}}\theta _ { s s } -b_{-2}{k_{-2dc}C_{M^{+2}_{sol}}(1-\theta _ { s s })}}{k_{1dc}+k_{2dc}+{k_{-2d}C_{M^{+2}_{sol}}+{j??}}}$

Accepted Answer

The answer of Consider the reaction given by \[\begin{array} {...

Question 12

Consider the reaction given by $$\begin{array} { l } M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \ \ M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - } \end{array}$$ . -In the same mechanism, the faradaic impedance (Z_F) is given by $$i _ { F } = F \left[ k _ { 1 } ( 1 - \theta ) + k _ { 2 } \theta - k _ { - 2 } ( 1 - \theta ) C _ { M _ { \mathbf { sol } } ^ { +2 } } \right]$$ A) $$\left( Z _ { F } \right) ^ { - 1 } = F \left( b _ { 1 } k _ { 1 dc } \left( 1 - \theta _ { ss } \right) + b _ { 2 } k _ { 2 d { c } } \theta _ { ss } - b _ { - 2 } k _ { - 2 d c } C _ { M _ {sol } ^ { +2 } } \left( 1 - \theta _ { s s } \right) - \left( k _ { 1 d c } - k _ { 2 dc } + k _ { - 2 d c } C _ { M _ {sol} ^ {+ 2 } } \right) \frac { d \theta } { d E } \right)$$ B) $$\left( Z _ { F } \right) ^ { - 1 } = F \left( b _ { 1 } k _ { 1 d c } \left( 1 - \theta _ { ss } \right) + b _ { 2 } k _ { 2 d { c } } \theta _ { ss } - b _ { - 2 } k _ { - 2 d c } C _ { M _ {sol } ^ { +2 } } \left( 1 - \theta _ { s s } \right) - \left( k _ { 1 d c } - k _ { 2 dc } + k _ { - 2 d c } C _ { M _ {sol} ^ {+ 2 } } \right) \frac { d \theta } { d E } \right)$$ C) $$\left( Z _ { F } \right) ^ { - 1 } = F \left( b _ { 1 } k _ { 1 { dc } } \left( 1 - \theta _ { s s } \right) + b _ { 2 } k _ { 2 {dc } } \theta _ { ss } - \left( k _ { 1 { dc } } - k _ { 2 d { c } } + k _ { - 2 { dc } } C _ { M^{+2} _ { { sol } } } \right) \frac { d \theta } { d E } \right)$$ D) $$\left( Z _ { F } \right) ^ { - 1 } = F \left( b _ { 1 } k _ { 1 d c } \left( 1 - \theta _ { ss } \right) + b _ { 2 } k _ { 2 d { c } } \theta _ { ss } - b _ { - 2 } k _ { - 2 d c } C _ { M _ {sol } ^ { +2 } } \left( 1 - \theta _ { s s } \right) +\left( k _ { 1 d c } - k _ { 2 dc } + k _ { - 2 d c } C _ { M _ {sol} ^ {+ 2 } } \right) \frac { d \theta } { d E } \right)$$

Accepted Answer

The answer of Consider the reaction given by \[\begin{array} {...

Question 13

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-The complex plane plot of impedance spectra of the above reaction can exhibit at the most ______ loops

Accepted Answer

The answer of Consider the reaction given by \[\begin{array} {...

Question 14

Consider the reaction given by $$\begin{array} { l } 
M \stackrel { k _ { 1 } } { \longrightarrow } M _ { ads } ^ { + } + e ^ { - } \
\
M _ { a d s} ^ { + } \frac { k _ { 2 } } { \longleftarrow k _ { - 2 } } M _ { s o l } ^ { 2 + } + e ^ { - }
\end{array}$$ .
-For the above mechanism, the mid and low-frequency data, in the complex plane plot can exhibit
A) capacitive loop
B) inductive loop
C) Warburg behavior
D) none of the above

Accepted Answer

The answer of Consider the reaction given by \[\begin{array} {...

Question 15

Negative real values of impedance indicate that
A) there is a problem in the measurement
B) when a potential is applied, current flows in the opposite direction
C) when potential is increased, current decreases
D) the phase difference between the potential and current is 180 °

Accepted Answer

The answer of Negative real values of impedance indicate that
A)...

Question 16

The polarization plot of an electrochemical system is given below. An impedance spectrum is acquired at some dc bias and shows hidden negative impedance.  The dc bias at which the spectrum was acquired could be
A) 0.4 V
B) 0.8 V
C) 1.2 V
D) none of the above

Accepted Answer

The answer of The polarization plot of an electrochemical system...

Question 17

Consider the reaction $$\begin{array} { l } P _ { s o l }\underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }Q _ { - s o l } + e ^ { - } \ A _ { s ol } ^ { - } \underset { k _ { - 2 } } { \stackrel { k _ { 2 } } { \rightleftarrows } } A _ { a d s } + e ^ { - } \ \end{array}$$ -The mass balance equation for fractional surface coverage of A_ads is given by A) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } \left[ P _ { s d } \right] - k _ { - 1 } \left[ Q _ { s ol } \right] + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] - k _ { - 2 } \theta$$ B) $$\Gamma \frac { d \theta } { d t } = k _ { 2 } \left[ A _ { s d } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta$$ C) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } \left[ P _ { s o l } \right] ( 1 - \theta ) - k _ { - 1 } \left[ Q _ { s o l } \right] \theta + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta$$ D) $$\Gamma \frac { d \theta } { d t } = k _ { 2 } \left[ A _ { s ol} ^ { - } \right] - k _ { - 2 } \theta$$

Accepted Answer

The correct mass balance equation for the fractional surface coverage ($\theta$) of $A_{ads}$ involves the rate of adsorption, which is proportional to the concentration of $A_{sol}^-$ and the available surface area ($1-\theta$), and the rate of desorption, which is proportional to the surface coverage ($\theta$). This is accurately represented in option B, where $k_2[A_{sol}^-](1-\theta)$ accounts for adsorption and $k_{-2}\theta$ for desorption.

Question 18

Consider the reaction $$\begin{array} { l } P _ { s o l }\underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }Q _ { - s o l } + e ^ { - } \ A _ { s ol } ^ { - } \underset { k _ { - 2 } } { \stackrel { k _ { 2 } } { \rightleftarrows } } A _ { a d s } + e ^ { - } \ \end{array}$$ -In the same reaction, the equation for fractional surface coverage of A_ads is given by A) $$\frac { k _ { 2 d c } \left[ A _ { s d } ^ { - } \right] } { k _ { 1 d \dot { k } } \left[ P _ { s o l } \right] - k _ { - 1 } \left[ Q _ { s o l } \right] + k _ { 2 d c } \left[ A _ { s o l } ^ { - } \right] + k _ { - 2 d c } }$$ B) $$\frac { k _ { 1 { dc} } \left[ P _ { s o l } \right] + k _ { 2 {dc } } \left[ A _ { sol } ^ { - } \right] } { k _ { 1 { dc } } \left[ P _ { s o l ] } \right] - k _ { - 1 } \left[ Q _ { s o l } \right] k _ { 2 { dc } } \left[ A _ { s ol } ^ { - } \right] + k _ { - 2 { dc } } }$$ C) $$\frac { k _ { 1 { dc } } \left[ P _ { s o l } \right] - k _ { - 1 } \left[ Q _ { s o l } \right] + k _ { 2{ dc } } \left[ A _ { s o l } ^ { - } \right] } { k _ { 1 \dot { k } } \left[ P _ { s o l } \right] - k _ { - 1 } \left[ Q _ { s o l } \right] + k _ { 2{dc } } \left[ A _ { s o l } ^ { - } \right] + k _ { - 2 { dc } } }$$ D) $$\frac { k _ { 2dc } \left[ A _ { s o l } ^ { - } \right] } { k _ { 2 dc } \left[ A _ { s o l } ^ { - } \right] + k _ { - 2 dc } }$$

Accepted Answer

The fractional surface coverage of $A_{ads}$ is determined by the rate of adsorption to the rate of desorption. The correct equation (D) reflects this by showing the rate of adsorption of $A_{sol}^{-}$ ($k_{2dc}[A_{sol}^{-}]$) over the sum of the rate of adsorption and the rate of desorption ($k_{-2dc}$), which correctly models the dynamics of surface coverage without involving the unrelated reaction components $P_{sol}$ and $Q_{sol}$.

Question 19

Consider the reaction $$\begin{array} { l } 
P _ { s o l }\underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }Q _ { - s o l } + e ^ { - } \
A _ { s ol } ^ { - } \underset { k _ { - 2 } } { \stackrel { k _ { 2 } } { \rightleftarrows } } A _ { a d s } + e ^ { - } \
\end{array}$$

-In the same reaction, the faradaic current is given by
A) $$i _ { F } = F \left\{ k _ { 1 } \left[ P _ { s o l } \right] ( 1 - \theta ) - k _ { - 1 } \left[ Q _ { s o l } \right] ( 1 - \theta ) + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta \right\}$$
B) $$i _ { F } = F \left\{ k _ { 1 } \left[ P _ { s o l } \right] ( 1 - \theta ) - k _ { - 1 } \left[ Q _ { s o l } \right] \theta + k _ { 2 } \left[ A _ { s ol } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta \right\}$$
C) $$i _ { F } = F \left\{ k _ { 1 } \left[ P _ { \text {sol } } \right] ( 1 - \theta ) - k _ { - 1 } \left[ Q _ { s o l } \right] ( 1 - \theta ) + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] - k _ { - 2 } \theta \right\}$$
D) $$i _ { F } = F \left\{ k _ { 2 } \left[ A _ { s a l } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta \right\}$$

Accepted Answer

The answer of Consider the reaction \[\begin{array} { l }...

Question 20

Consider the reaction $$\begin{array} { l } 
P _ { s o l }\underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }Q _ { - s o l } + e ^ { - } \
A _ { s ol } ^ { - } \underset { k _ { - 2 } } { \stackrel { k _ { 2 } } { \rightleftarrows } } A _ { a d s } + e ^ { - } \
\end{array}$$

-In the same reaction, the expression for $$\frac { d \theta } { d E }$$ 
is given by
A) $$\frac { d \theta } { d E } = \frac { b _ { 2 } k _ { 2dc } \left[ A _ { so l } ^ { - } \right] - b _ { - 2 } k _ { - 2 dc} } { k _ { 2 dc } \left[ A _ { s ol } ^ { - } \right] + k _ { - 2  { dc} } + j \omega \Gamma }$$
B) $$\frac { d \theta } { d E } = \frac { b _ { 2 } k _ { 2 dc } \left[ A _ { s ol } ^ { - } \right] \left( 1 - \theta _ { ss } \right) - b _ { - 2 } k _ { - 2 dc } \theta _ { s s } } { k _ { 2 d c} \left[ A _ { so l } ^ { - } \right] \left( 1 - \theta _ { s s } \right) + k _ { - 2 dc } \theta _ { ss } + j \omega \Gamma }$$
C) $$\frac { d \theta } { d E } = \frac { b _ { 2 } k _ { 2dc } \left[ A _ { s o l } ^ { - } \right] \left( 1 - \theta _ { s s } \right) - b _ { - 2 } k _ { - 2 dc } \theta _ { s s } } { k _ { 2 dc } \left[ A _ { s o l } ^ { - } \right] + k _ { - 2 dc } + j \omega \Gamma }$$
D) $$\frac { d \theta } { d E } = \frac { b _ { 2 } k _ { 2 dc } \left[ A _ { s o l } ^ { - } \right] - b _ { - 2 } k _ { - 2 d c } } { k _ { 2 d \dot { } } \left[ A _ { s o l } ^ { - } \right] \left( 1 - \theta _ { s s } \right) + k _ { - 2 d c } \theta _ { s s} + j \omega \Gamma }$$

Accepted Answer

The answer of Consider the reaction \[\begin{array} { l }...

Quiz 5: Mechanistic Analysis

A Frumkin isotherm model will reduce to Langmuir isotherm when parameter "g" is _____

Temkin model describes the relationship between _______ and fractional surface coverage

Consider the reaction $\left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] ^ { 4 - } \underset { k _ { - 1 } } { \longleftarrow } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] ^ { 3 - } + e ^ { - }$ The net reaction rate is given by

A unique method of representing impedance spectrum is

Negative real values of impedance indicate that

The polarization plot of an electrochemical system is given below. An impedance spectrum is acquired at some dc bias and shows hidden negative impedance. The dc bias at which the spectrum was acquired could be

Quiz 5: Mechanistic Analysis

A Frumkin isotherm model will reduce to Langmuir isotherm when parameter "g" is _____

Temkin model describes the relationship between _______ and fractional surface coverage

The following impedance spectrum was obtained for an electrochemical system. Which of the following mechanisms can be considered to describe the electrochemical system?

A unique method of representing impedance spectrum is

Negative real values of impedance indicate that

The polarization plot of an electrochemical system is given below. An impedance spectrum is acquired at some dc bias and shows hidden negative impedance. The dc bias at which the spectrum was acquired could be