Electrochemistry · Chemistry · TS EAMCET
MCQ (Single Correct Answer)
The order of negative standard potential values of Li, $\mathrm{Na}, \mathrm{K}$ is
At 298 K the equilibrium constant for the reaction $M(s)+2 \mathrm{Ag}^{+}(a q) \longrightarrow M^{2+}(a q)+2 \mathrm{Ag}(s)$ is $10^{15}$. What is the $E_{\text {cell }}^{\ominus}$ (in V) for this reaction?
$$ \left(\frac{2.303 R T}{F}\right)=0.06 \mathrm{~V} $$
A current of 0.5 ampere is passed through molten $\mathrm{AlCl}_3$ for 96.5 seconds. The mass of aluminium deposited at cathode is $x \mathrm{mg}$ and volume of chlorine liberated (at STP) at anode is $y \mathrm{~mL} . x$ and $y$ are respectively.
The mole conductivity of acetic acid solution at infinite dilution is $390 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$. What is the molar conductivity of 0.01 M acetic acid solution (in $\mathrm{S} \mathrm{cm}^2 \mathrm{~mol}^{-1}$ )?
(Given $K_a\left(\mathrm{CH}_3 \mathrm{COOH}\right)=1.8 \times 10^{-5}$, assume $1-\alpha=1$ )
The incorrect statement about Castner-kellner cell process is
The incorrect statement about Castner-kellner cell process is
The Gibbs energy change of the reaction (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) corresponding to the following cell
$\mathrm{Cr}\left|\mathrm{Cr}^{3+}(0.1 \mathrm{M}) \| \mathrm{Fe}^{2+}(0.001 \mathrm{M})\right| \mathrm{Fe}$
(Given $E_{\mathrm{Cr}^{3+} \mid \mathrm{Cr}}^{\circ}=-0.75 \mathrm{~V} ; E_{\mathrm{Fe}^{2+} \mid \mathrm{Fe}}^{\circ}=-0.45 \mathrm{~V}$,
$\left.\mathrm{IF}=96,500 \mathrm{C} \mathrm{mol}^{-1}\right)$
Electrolysis of aqueous copper (II) sulphate between Pt electrodes gives ' $X^{\prime}$ at anode and ' $Y^{\prime}$ at cathode. $X$ and $Y$ are respectively.
At 298 K , if emf of the cell corresponding to the reaction $\mathrm{Zn}(s)+2 \mathrm{H}^{+}(a q) \longrightarrow \mathrm{Zn}^{2+}(0.01 \mathrm{M})+\mathrm{H}_2(g) (1 \mathrm{~atm})$ is 0.28 V , then the pH of the solution at the hydrogen electrode is $\left(\frac{2.303 R T}{F}=0.06 \mathrm{~V}\right)$, $\left(E_{\mathrm{Zn}^{2+} / \mathrm{Zn}}^{\circ}=-0.76 \mathrm{~V}\right)$
0.592 g of copper is deposited in 60 minutes by passing
0.5 A current through a solution of copper (II) sulphate. The electro chemical equivalent of copper (II) (in $\mathrm{gC}^{-1}$ ) is
( $F=96500 \mathrm{C} \mathrm{mol}^{-1}$ )
Two statements are given below.
Statement I : Molten NaCl is electrolysed using Pt electrodes. $\mathrm{Cl}_{2}$ is liberated at anode.
Statement II : Aqueous $\mathrm{CuSO}_{4}$ is electrolysed using Pt electrodes. $\mathrm{O}_{2}$ is liberated at cathode.
The correct answer is
Identify the correct statements from the following
(A) At 298 K , the potential of hydrogen electrotle placed in a solution of $\mathrm{pH}=10$, is -0.59 V
(B) The limiting molar conductivity of $\mathrm{Ca}^{2+}$ and $\mathrm{Cl}^{-}$is 119 and $76 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ respectively. The limiting molar conductivity of $\mathrm{CaCl}_2$ is $195 \mathrm{Scm}^2 \mathrm{~mol}^{-1}$
(C) The correct relationship between $K_C$ and $E_{\text {cell }}^{\ominus}$ is $$ E_{\text {cell }}^\theta=\frac{2303 R T}{n F} \log K_C $$
The reduction potential of a half-cell consisting of a Pt electrode immersed in $2.0 \mathrm{M} \mathrm{Fe}^{2+}$ and $0.02 \mathrm{M} \mathrm{Fe}^{3+}$ solution (in V) is
Given : $\left(\frac{2.303 R T}{F}=0.059, E_{\mathrm{Fe}^{3+} \mid \mathrm{Fe}^{2+}}^{\circ}=0.771 \mathrm{~V}\right)$
A current of 15.0 A is passed through a solution of $\mathrm{CrCl}_2$ for 45 minutes. The volume of $\mathrm{Cl}_2$ (in L ) obtained at the anode at 1 atm and 273 K is around (IF $=96500 \mathrm{C} \mathrm{mol}^{-1}$, atomic wt. of $\mathrm{Cl}=35.5, R=0.082 \mathrm{L}-\mathrm{atm} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ )
$A$ and $B$ are two metals. The standard reduction potential of $A^{+}(a q) / A(s)$ and $B^{+}(a q) / B(s)$ are -0.5 V and +0.5 V respectively. What is the $\log K_c$ value for the following reaction at 298 K ?
$$ \begin{aligned} & A(s)+B^{+}(a q) \rightleftharpoons A^{+}(a q)+B(s) \\ & \left(\text { Given }: \frac{2.303 R T}{F}=0.06 \mathrm{~V}\right) \end{aligned} $$
The conductivity of a solution of concentration $0.1 \mathrm{~mol} \mathrm{~L}^{-1}$ of a weak monobasic acid $(\mathrm{HA})$ (in $\mathrm{S} \mathrm{cm}^{-1}$ ) is (Given : $\Lambda^{\circ}{ }_{\mathrm{HA}}=400 \mathrm{Scm}^2 \mathrm{~mol}^{-1}$ and degree of dissociation ( $\alpha$ ) of $\mathrm{H} A=0.02$ )
At 300 K , the conductivity of $0.01 \mathrm{~mol} \mathrm{dm}^{-3}$ aqueous solution of acetic acid is $19.5 \times 10^{-5} \mathrm{mho} \mathrm{cm}^{-1}$ and limiting molar conductivity of acetic acid at the same temperature is $390 \mathrm{mho} \mathrm{cm}^2 \mathrm{~mol}^{-1}$. The degree of dissociation of acetic acid is
The $E^{\circ}$ of $\mathrm{Ce}^{4+} / \mathrm{Ce}^{3+}=1.6 \mathrm{~V}, \mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}=0.76 \mathrm{~V}$ the $E^{\circ}$ of $\mathrm{Fe}^{3+}$ oxidising $\mathrm{Ce}^{3+}$ is
Electrolysis of aqueous $\mathrm{Na}_2 \mathrm{SO}_4$ was carried out by passing a current of 3 ampere for 10 min . The volume of the gas (in litre) at STP at the anode of the cell is approximately
The variation of $\lambda_{\mathrm{m}}$ of acetic acid with concentration is correctly represented as
In two separate experiments, the same quantity of electricity was passed through silver and gold solutions. [Assume ' $l$ ' constant]. The amounts of Ag and Au deposited are 2.15 and 1.31 g , respectively. The valency of gold is
[atomic mass of $\mathrm{Ag}=107.9$; $\mathrm{Au}=197$ ]
Given, $E_{\mathrm{Mn}^{7+} / \mathrm{Mn}^{2+}}^{\circ}=1.51 \mathrm{~V}, E_{\mathrm{Mn}^{4+} / \mathrm{Mn}^{2+}}^{\circ}=1.23 \mathrm{~V}$ Calculate the $E_{\mathrm{Mn}^{7+} / \mathrm{Mn}^{4+}}^{\circ}$.
On passing a current of 1.2 A through a solution of salt of copper for $40 \mathrm{~min}, 0.96 \mathrm{~g}$ of copper was deposited. The equivalent weight of copper in g is
$\mathrm{Mg}^{2+}$ displaces hydrogen from acids but copper does not. A galvanic cell prepared by combining $\mathrm{Cu} / \mathrm{Cu}^{2+}$ and $\mathrm{Mg} / \mathrm{Mg}^{2+}$ has an EMF of 2.71 V at 298 K . If the potential of copper electrode is 0.34 V , what is the reduction potential of Mg electrode?
Copper is to be electrodeposited on a nickel block of $(20 \times 5) \mathrm{cm}^2$ area by using $\mathrm{CuSO}_4$ as electrolyte. How much quantity of electricity is needed to deposit a 3.6 $\mu \mathrm{m}$ layer of copper?
[Atomic weight of $\mathrm{Cu}=63.5 \mathrm{~mol}^{-1}$ Density of $\mathrm{CuSO}_4=8.9 \mathrm{~g} / \mathrm{cc}$ ]
A solution of $\mathrm{Fe}^{2+}$ is titrated potentiometrically using $\mathrm{Ce}^{4+}$ solution. When $80 \% \mathrm{Fe}^{2+}$ is titrated, the EMF of the system in $V$ is
(Given, $E^{\circ} \mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}=0.77 \mathrm{~V}$ and $\left.\mathrm{Fe}^{2+}+\mathrm{Ce}^{4+} \longrightarrow \mathrm{Fe}^{3+}+\mathrm{Ce}^{3+}\right) (\log 2=0.3, \log 3=0.5, \log 4=0.6)$
What is the standard cell potential for the reaction with $K=1$ (equilibrium constant)
The maximum work that can be obtained from the following cells is
$$ X\left|X^{2+}(a q) \| Y^{+}(a q)\right| Y $$
Given, $E_{X^{2+} / X}^{\circ}=-1.7 \mathrm{~V}, E_{Y^{2+} / Y}^{\circ}=0.8 \mathrm{~V}$
The standard electrode potentials of $\mathrm{Ag}^{+} / \mathrm{Ag}$ is +0.80 V and $\mathrm{Cu}^{+} / \mathrm{Cu}$ is +0.34 V . If these electrodes are connected through a salt-bridge, which of the following statements is correct?