List of top Chemistry Questions on Nernst Equation

Observe the following cell \[ M(s)\;|\;M^{2+}(xM)\;||\;H^+(0.02M)\;|\;H_2(g,1\,bar)\;,\;Pt(s) \] What is the value of \(x\)? Given: \[ \frac{2.303RT}{F}=0.06V \] \[ E^\circ_{M^{2+}|M}=-0.14V \] \[ E^\circ_{H^+|H_2}=0.0V \] \[ E_{cell}=0.077V \] \[ \log 4=0.602 \] \[ \text{antilog}(2.7)=0.05,\qquad \text{antilog}(2.60)=0.04 \]

Consider the cell at 298 K: $Mg(s)|Mg^{2+}(1.0M)||Cu^{2+}(1.0M)|Cu(s)$. How can we increase the emf of the cell using the same substances?

Consider the following cell at \( 298 \, K \): \( Mg (s) \mid Mg^{2+} (1.0 \, M) \parallel Cu^{2+} (1.0 \, M) \mid Cu (s) \). How can we increase the emf of the cell using the same substances ?

Calculate emf of the following cell at 298 K:
$Sn | Sn^{2+}(0.001~M) || H^+(0.01~M) | H_{2(g)}(1~bar) | Pt_{(s)}$
Given: $E^\circ_{Sn^{2+}/Sn} = -0.14~V$, $E^\circ_{H^+/H_2} = 0.00~V [\log 10 = 1]$

Calculate emf of the following cell at 298 K :
\( \text{Sn} \mid \text{Sn}^{2+} (0.001 \text{ M}) \parallel \text{H}^+ (0.01 \text{ M}) \mid \text{H}_{2(g)} (1 \text{ bar}) \mid \text{Pt}_{(s)} \)
Given : \( E^\circ_{\text{Sn}^{2+}/\text{Sn}} = - 0.14 \text{ V}, \quad E^\circ_{\text{H}^+/\text{H}_2} = 0.00 \text{ V} \quad [\log 10 = 1] \)

Calculate emf of the following cell at 298 K :
\( \text{Zn (s)| Zn}^{2+}\text{(aq) (0.1 M)|| Ag}^+\text{ (aq) (0.01 M)|Ag (s)} \)
(Given : \( E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76 \text{ V}, E^\circ_{\text{Ag}^{+}/\text{Ag}} = +0.80 \text{ V, [log 10 = 1]} \))

Calculate the electrode potential of a half-cell for zinc electrode dipping in \(0.01\,M\) \(ZnSO_4\) solution at \(25^\circ C\). \[ \text{Given : } E^\circ_{Zn^{2+}/Zn}=-0.76\,V \] \[ \log 10 = 1 \]

Calculate emf of the following cell at \(298\,K\) : \[ Cr(s)\,|\,Cr^{3+}(aq,\;0.1\,M)\,||\,Fe^{2+}(aq,\;0.01\,M)\,|\,Fe(s) \] (Given : \[ E^\circ_{Cr^{3+}/Cr}=-0.74\,V, \] \[ E^\circ_{Fe^{2+}/Fe}=-0.44\,V, \] \[ \log 10 = 1 \] )

Answer the following: \[ (a)(i)\;\text{Calculate the electrode potential of a half-cell for zinc electrode dipping in }0.01M\;ZnSO_4\text{ solution at }25^\circ C. \] \[ E^\circ_{Zn^{2+}/Zn}=-0.76V,\quad \log 10=1 \] \[ (a)(ii)\;\text{Write anode, cathode and overall reaction involved in dry cell.} \] \[ (a)(iii)\;\text{Equilibrium constant }(K_c)\text{ is related to }E^\circ_{\text{cell}},\text{ but not to }E_{\text{cell}}.\text{ Why?} \]

For the reaction:
2 AgCl(s) + H₂(g) (0.4 atm) → 2 Ag(s) + 2 H⁺(0.1 M) + 2 Cl^-(0.2 M)
Calculate the emf of the cell at 25 °C.
Given: ΔG° = -43500 J mol^-1. [log 10 = 1, 1 F = 96500 C mol^-1]

Calculate emf and ΔG for the following cell at 298 K:
Mg(s) | Mg²⁺(0.01 M) || Ag⁺(0.001 M) | Ag(s)
Given: E°_Mg²⁺/Mg = -2.37 V, E°_Ag⁺/Ag = +0.80 V. [1 F = 96500 C mol^-1, log 10 = 1]

Answer the following:

(i) Why is the Equilibrium Constant \(K_c\) related to \(E^\circ_{cell}\) and not to \(E_{cell}\)?

(ii) Two metals 'A' and 'B' have standard electrode potential values of \(-0.24\) V and \(+0.80\) V respectively. Which of these will liberate hydrogen gas from dil. \(H_2SO_4\)?

(iii) Write the cell reaction which occurs in lead storage battery when it is in charging.

Calculate the electrode potential of a half-cell for a zinc electrode dipping in 0·01 M $\mathrm{ZnSO_4}$ solution at 25°C. [Given : $\mathrm{E^\circ_{Zn^{2+}/Zn} = -0.76\,V}$, log 10 = 1]

Equilibrium constant $\mathrm{(K_c)}$ is related to $\mathrm{E^\circ_{cell}}$, but not to $\mathrm{E_{cell}}$. Why ?

The following reaction takes place in a cell at 298 K: $2M^{3+}(aq) + 2I^{-}(aq) \rightarrow 2M^{2+}(aq) + I_2(s)$. What is the value of $\log K_c$ for this reaction? (Given: $E_{cell}^\circ = 0.235 V, F = 96500 C mol^{-1}, R = 8.3 J mol^{-1} K^{-1}$)

The emf values of three galvanic cells I, II and III are \(E_1\), \(E_2\) and \(E_3\) respectively. Determine the correct order among them. \[ \text{(I)}\quad Zn|Zn^{2+}(1M)||Cu^{2+}(0.1M)|Cu \] \[ \text{(II)}\quad Zn|Zn^{2+}(1M)||Cu^{2+}(1M)|Cu \] \[ \text{(III)}\quad Zn|Zn^{2+}(0.1M)||Cu^{2+}(1M)|Cu \]

If \( E^\circ (Ag^+ | Ag) = +0.80 \, V \), What is the potential developed for \( Ag (s) \rightarrow Ag^+ (0.01M) + e^- \) at 298 K?

For $Zn(s)+Cu^{2+}(0.1M) \rightarrow Zn^{2+}(0.001 M)+Cu(s)$, calculate $E_{cell}$ if $E^0_{cell} = 1.1V$. ________.

For the cell reaction, $A_{(s)}+B_{(aq)}^{2+}\rightarrow A_{(aq)}^{2+}+B_{(s)}$ if equilibrium constant of reaction is $10^{4}$ at 298 K. What is standard emf of cell?

If $E^{\circ}(\text{Cu}^{2+}/\text{Cu})=+0.34\text{ V}$. What is potential for $\text{Cu}(s)\rightarrow \text{Cu}^{2+}(aq)(0.1\text{M})+2e^{-}$ at 298 K?

What happens to the emf for the cell, $Zn|Zn_{(aq)}^{2+}||Ag_{(aq)}^{+}|Ag_{(s)}$ if concentration of $Ag^{+}$ decreases to 0.1 M?

What is reduction potential of hydrogen gas electrode when pure hydrogen gas is at 1 atmospheric pressure and platinum electrode is in contact with HCl solution of pH 1 at 298 K?

The EMF of the cell \(Al/Al^{3+}(0.01M) \parallel Fe^{2}+(0.02M)/Fe\) is 1.209 V. The EMF of the cell can be increased by

Given the reaction: \[ \text{Cu(s)} + 2\text{Ag}^+_{(aq)} \rightleftharpoons \text{Cu}^{2+}_{(aq)} + 2\text{Ag(s)} \quad (\text{E}_{\text{cell}}^\circ = 0.295 \, \text{V}, \, 2.303 \, \frac{RT}{F} = 0.059 \, \text{V}) \] What is the value of the equilibrium constant \( K \)?

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1000 ohm. What is the cell constant if conductivity of 0.001 M KCl solution at 298 K is 0.125 × 10−3 S cm−1?