Recent questions tagged electrochemistry

Consider the electrochemical cell :$Zn (s) / Zn^{2+} (aq) // Cu^{2+} (aq) / Cu.$ It has an electrical potential of 1.1 V when concentration of $Zn^{2+}$ and $Cu^{2+}$ ions is unity.State the direction of flow of electrones and also specify if Zinc and Copper aredeposited or dissolved at their respective electrodes. When :(a) an external opposite potential of 0.8 V is applied.(b) an external opposite potential of 1.1 V is applied.(c) an external opposite potential of 1.4 V is applied.

asked Dec 29, 2016 by sharmaaparna1

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(i) In a cell reaction, the equilibrium constant K is less than one. Is E° for the cell positive or negative ? (ii) What will be the value of K of $E^{\circ}$ cell = 0 ?

asked Dec 29, 2016 by sharmaaparna1

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Iron and nickel are used to make electro chemical cell by using a salt bridge to join a half cell containing $1\;M\;Fe^{2+}(aq)$ in which a strip of irons has been immersed to a second half cell which contain $1\;M\;Ni^{2+}(aq)$ in which a strip of Ni has been immersed ? A voltmeter is connected between the two metal strips : $E^{0} _{Fe^{2+}/Fe} =-0.44 V; \qquad E^{0} _{Ni^{2+}/Ni} =-0.25 V $ a) Write the name of the cathode and anode . b) Write the half reaction involved ? c) What would be the effect on the voltmeter reading if $Fe^{2+}$ concentration were increased ?

asked Nov 24, 2016 by meena.p

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Which of the following pair will have greater conduction and why ? (a) Copper wire at $25^{\circ}C$ and copper wire at $50^{\circ}C$. (b) $0.1\; M$ acetic acid solution or $1\;M$ acetic acid solution?

asked Nov 24, 2016 by meena.p

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The following curve is obtained when molar conductivity $(\lambda_m)$ is plotted against the square root of concentration for 2 electrolytes A and B (a) What can you say about the nature of the two electrolyte $A\; \&\;B$ (b) How do you account for the increase in molar conductivity $\lambda_m$ for the electrolyte A and B on dilution

asked Nov 21, 2016 by meena.p

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The conductivity of $0.20\;M$ solution of KCl at $298\;K$ is $0.0248 \;Scm^{-1}$ Calculate its molar conductivity

asked Nov 21, 2016 by meena.p

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Out of C and CO, Which is better reducing agent at $673\;k$

asked Nov 9, 2016 by meena.p

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Why is boiling point of water increased on addition of sodium chloride into it ?

asked Nov 4, 2016 by meena.p

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Calculate the equilibrium constant $K_c$ for the reaction . $3Sn^{4+} +2Cr \to 3Sn^{2+}+2Cr^{3+}$Given $E^0 =0.885\;V$

asked Nov 4, 2016 by meena.p

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What would happen if no salt bridge were used in an electro chemical cell (like Zn-Cu cell)?

asked Nov 3, 2016 by meena.p

1 answer

(a) Define molar conductivity of a solution and explain how molar conductivity changes with change in concentration of solution for a weak and a strong electrolyte (b) The resistance of a conductivity cell conatining $0.001\;M\;KCL$ Solution at $298\;K$ is $1500 \;\Omega$ . What is the cell constant if the conductivity of $0.001\;M\;KCl$ solution at $298\;K$ is $0.146 \times 10^{-3} \;S \;cm^{-1}$ ?

asked Nov 1, 2016 by meena.p

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Identify the anode and cathode in the cell written below :$Cu | Cu^{2+}| |Cl^{-} ||Cl_2, Pt$ write the reduction half reaction and oxidation half reaction of the cell

asked Nov 1, 2016 by meena.p

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What type of a battery is the lead storage battery ? write the anode and the cathode reaction occurring in a lead storage battery when current is drawn from it .

asked Oct 26, 2016 by meena.p

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Resistance of a conductivity cell filled with $0.1\;mol L^{-1}KCl$ solution is $100\;\Omega$ . If the resistance of the same cell when filled with $0.02\;molL^{-1}\;KCl$ Solution . The conductivity of $0.02\;mol L^{-1}KCl$ Solution . The conductivity of $0.1\;mol\;L^{-1}$ Solution is $1.29\;s/m$

asked Oct 26, 2016 by meena.p

1 answer

The resistance of the conductivity cell containing $0.001\;M\;KCl$ solution at $298\;K$ is $1500\Omega$. What is the cell constant if conductivity of $0.001\;M\;KCl$ solution at $298\;K$ is $0.14 \times 10^{-3} 5\;cm^{-1}? $

asked Oct 21, 2016 by meena.p

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Explain the role of (a) Cryolite in the electrolytic reduction of alumina . (b) carbon monoxide in the purification of nickel

asked Oct 21, 2016 by meena.p

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Out line the principle of the method used for refining of (a)Nickel (b)Zirconium (c) Tin

asked Oct 19, 2016 by meena.p

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Resistance of a conductivity cell filled with $0.1 \;mol^{-1}KCl$ solution is $100 \Omega$ . If the resistance of the same cell when filled with $0.2\;mol L^{-1}\;KCl$ solution is $520\; \Omega$ . Calculate the conductivity of $0.2 mol L^{-1} \;KCl$ solution . The conductivity of $0.1\;mol L^{-1} KCl$ solution is $1.29\;s.m$

asked Oct 14, 2016 by meena.p

1 answer

$H_3PO_4$ is a tribasic acid and one of its salts is $NaH_2PO_4$. What volume of $1\; M\; NaOH$ solution should be added to $12\; g$ of $NaH_2PO_4$ to convert it into $Na_3PO_4$ ? $(H = 1, O = 16, Na = 23, P = 31)$

asked Jan 18, 2016 by meena.p

1 answer

For which electrolyte $ac= \large\frac{\lambda v}{\lambda \infty}$ dosen't hold good ?

asked Sep 21, 2015 by meena.p

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What is the number of moles of oxygen gas evolves by electrolysis of $180\;g$ of $H_2O$?

asked Sep 21, 2015 by meena.p

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The emf of a cell containing sodium / copper electrodes is $3.05\;V$ , if the electrode potential of copper electrode is $0.34\;V$ , the electrode potential of sodium is

asked Sep 21, 2015 by meena.p

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How long (in hrs) must a current of 5 ampere be maintained to electroplate 60 g of calcium from molten $cacl_2$

asked Sep 21, 2015 by meena.p

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For strong electrolytes , the plot of molar conductance versus $\sqrt 3$ is :

asked Sep 21, 2015 by meena.p

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The reduction potential of hydrogen halfcell will be negative if

asked Sep 21, 2015 by meena.p

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The electrode reaction takes place at the anode of $CH_2 -O_2$ fuel cell is

asked Sep 21, 2015 by meena.p

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The tendencies of the electrodes made up of $Cu,Zn$ and $Ag$ to release electrons when dipped in their respective salt solutions decreases in the order .

asked Sep 21, 2015 by meena.p

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The reduction potential values of M, N and o are $+2.46\;V,-1.13\;V,-3.13\;V$ respectively . Which of the following orders is correct regarding their reducing property ?

asked Sep 21, 2015 by meena.p

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What are the units of equivalent conductivity of a solution ?

asked Sep 21, 2015 by meena.p

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The half - cell reaction for the corrosion $2H^++frac{1}{2}O_2+2e^{-}\to H_2O ; \in^0=1.23\;V \\ Fe^{2+}+2e^{-} \to Fe_{r} ; \in^0=-0.44\;V$

asked Sep 21, 2015 by meena.p

1 answer

The standard reaction potential $\in ^0$ for the half reaction are: $Zn \to Zn^{2+}+2e^{-}; \in^0 =0.76\;V; Cu \to Cu^{2+}+2e^{-} ;\in ^0 =0.34\;V$ The emf for the cell reach ,$2n(r) +cu^{2+}\to Zn^{2+}+Cu(r)$

asked Sep 21, 2015 by meena.p

1 answer

In which of the following cells will be the emf be independent of the activity of the chloride ions ?

asked Sep 21, 2015 by meena.p

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Which of the following reactions is possible at anode ?

asked Sep 21, 2015 by meena.p

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The charge required to deposit 9 g of $Al$ from $Al^{3+}$ solution is (At wt of AI=27.0)

asked Sep 21, 2015 by meena.p

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The quantity of electricity needed to deposit $127.08\;g$ of Copper is

asked Sep 21, 2015 by meena.p

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The quantity of electricity needed to deposit $127.08\;g$ of copper is :-

asked Sep 21, 2015 by meena.p

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When $9.65$ coulomb of electricity is passed through a solution of silver nitrate (At mass of Ag $=108\;g\;mol^{-1} $) the amount of silver deposited is

asked Sep 21, 2015 by meena.p

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What is the amount of chlorine evolved when 2 ampere of current is passed for $30$ minutes in an aqueous solution of $Nacl$

asked Sep 21, 2015 by meena.p

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In the electro chemical reaction : $2Fe^{3}+Zn \to 2n^{2+} +2 Fe^{2+}$

asked Sep 21, 2015 by meena.p

1 answer

As a lead storage battery is charged :-

asked Sep 21, 2015 by meena.p

1 answer

The standard reduction potential values of three metallic cation x,y and z are $0.52,3.03$ and $ -1.18\;v$ respectively . The order of reducing powers of the corresponding metal is :

asked Sep 21, 2015 by meena.p

1 answer

The standard reduction potential for $Cu^+ / Cu $ an $Cu^{2+} /Cu^+$ are $0.337\;V$ and $0.153\;V$ respectively . The standard electrode potential of $Cu^+/Cu$ half cell is

asked Sep 21, 2015 by meena.p

1 answer

The number of coulombs required for the deposition of $107.87\;g$ of silver is

asked Sep 21, 2015 by meena.p

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The amount of silver deposited on passing $2F$ of electricity through aqueous solution of $AgNo_3$ is :

asked Sep 21, 2015 by meena.p

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The standard electrode potentials of $zn,Ag$ and $Cu$ are $-0.76,0.80$ and $0.34$ volt respectively ; then

asked Sep 21, 2015 by meena.p

1 answer

An example of a simple fuel cell is

asked Sep 21, 2015 by meena.p

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When a lead storage battery is charged :-

asked Sep 21, 2015 by meena.p

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Which of the following solutions of NaCl will have the highest specific conductance ?

asked Sep 21, 2015 by meena.p

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What is the number of coulomb required for the conversion of one mole of $Mno^{-}4$ to one mole of $Mn^{2+}$?

asked Sep 21, 2015 by meena.p

1 answer

How many silver will be obtained by that quantity of current which displaces $5.6$liters of $H_2$ ?

asked Sep 21, 2015 by meena.p

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