Recent questions tagged ch-3

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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How would you account for the following (i) Aldehydes are more reactive than ketones towards nucleophiles (ii) The boiling points of aldehydes and ketones are lower than of the corresponding acids (iii) The aldehydes and ketones undergo a number of addition reactions.

asked Nov 25, 2016 by meena.p

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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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Let $F(x) =\begin{pmatrix} \cos x & -\sin x & 0 \\ \sin x & cos x & 0 \\ 0 & 0 & 1 \end{pmatrix} $ Show that F(x) F(y) = F (x+y)

asked Nov 10, 2016 by priyanka.c

1 answer

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

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(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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What is the difference between physisorption and chemisorption?

asked Oct 17, 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

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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

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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

1 answer

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

1 answer

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

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