Recent questions tagged class12

The magnitude of electric filed as a function of the distance r inside the sphere is given by

asked Feb 18, 2014 by yamini.v

1 answer

Which of the following compound is expected to have maximum enol content in ethanol?

asked Feb 18, 2014 by sreemathi.v

1 answer

The reaction $CH_3COCH_3 \large\xrightarrow{[H^+]} CH_3CH_2CH_3$ is known as

asked Feb 18, 2014 by sreemathi.v

1 answer

The Edison storage cell is represented as $Fe(s)/FeO(s)/KOH(aq)/Ni_2O_3(s)/Ni(s)$.The half cell reactions are $Ni_2O_3(s)+H_2O(l)+2e^-\rightarrow 2NiO(s)+2OH^-(aq)\Rightarrow E^0=0.4V$,$FeO(s)+H_2O(l)+2e^-\rightarrow Fe(s)+2OH^-(aq)\Rightarrow E^0=-0.87.V$.What will be the maximum amount of electrical energy that can be obtained from one mole of $Ni_2O_3$

asked Feb 18, 2014 by sreemathi.v

1 answer

Two plane mirrors A and B are aligned parallel to each other as shown. A light ray is incident at an angle of $30^{\circ}$ at a point just inside one end of A. The plane of incidence coincides with place of figure. The maximum number of time the ray undergoes reflections (including the first one ) before it emerges out is

asked Feb 18, 2014 by meena.p

1 answer

There are two concentric spherical shells of radii r and 2r . Initially a charge Q is given to the inner shell . Now , switch $\;S_{1}\;$ is closed and opened then $\;S_{2}\;$ is closed and opened and the process is repeated n times for both the keys alternatively . Find the final potential difference between the shells

asked Feb 18, 2014 by yamini.v

1 answer

The Edison storage cell is represented as $Fe(s)/FeO(s)/KOH(aq)/Ni_2O_3(s)/Ni(s)$.

asked Feb 18, 2014 by sreemathi.v

1 answer

In the ideal YDSE , when a glass plate $(refractive index\;1.5)$ of thickness t is introduced in path of one of interfering beams (wave - length $\lambda$) the intensity at position where central maximum occurred preciously remains unchanged . The minimum thickness of glass plate is :

asked Feb 18, 2014 by meena.p

1 answer

$H_2O_2$ can be prepared by successive reactions

asked Feb 18, 2014 by sreemathi.v

1 answer

The voltage of cell given is -0.46V $Pt/H_2$(atm)/$NaHSO_3(0.4M),Na_2SO_3(6.44\times 10^{-3}M)\parallel Zn^{+2}(0.3M)/Zn(g)$.Also $Zn^{+2}+2e^-\rightarrow Zn(s) \leftrightharpoons E^0=-0.763$V.Then the value of $K_2=\large\frac{[H^+][SO_3^{-2}]}{[HSO_3^-]}$

asked Feb 18, 2014 by sreemathi.v

1 answer

1.26gm weight of NaOH required to be added in R.H.S to consume all the $H^+$ present in R.H.S of cell of emf to .701V at $25^{\large\circ}C$.Given: $Zn/Zn^{+2}(0.1M)\parallel HCl$(1litre)$/H_2/$(1atm)/P:-$E^0_{Zn/Zn^{+2}}=0.7602$.The emf of cell after addition of NaOH will be

asked Feb 18, 2014 by sreemathi.v

1 answer

A simple pendulum with a bob of mass m=1 kg , charge $5\;mu C \;$ and string length l=1m is given a horizontal velocity u in a uniform electric field $\;E=2\times10^{6} V/m\;$ at its bottom most point as shown in figure . It is given that the speed u is such that the particle leaves the circle at point C . Find approx the speed u in m/s (Take g=10 m/s^2)

asked Feb 18, 2014 by yamini.v

1 answer

Calculate the minimum weight of NaOH required to be added in R.H.S to consume all the $H^+$ present in R.H.S of cell of emf to .701V at $25^{\large\circ}C$.Given: $Zn/Zn^{+2}(0.1M)\parallel HCl$(1litre)$/H_2/$(1atm)/P:-$E^0_{Zn/Zn^{+2}}=0.7602$

asked Feb 18, 2014 by sreemathi.v

1 answer

Given the overall formation constant of the $[Fe(CN)_6]^{-4}$ ion as $10^{35}$ and the standard potential for half reaction $Fe^{+3}+e^-\leftrightharpoons Fe^{+2},E^0=0.77V$,$[Fe(CN)_6]^{-3}+e^-\leftrightharpoons [Fe(CN)_6]^{-4},E^0=0.36V$.Then the overall formation constant of $[Fe(CN)_6]^{-3}$ ion is

asked Feb 18, 2014 by sreemathi.v

1 answer

A mass m is to be placed on the rod of length L and pivoted at its centre at a distance x from the left end of the rod so that the system shown in figure remains in equilibrium . Find x (Ignore the force between Q (beaneth q ) and 2q and the force between Q (beneath 2q) and q .

asked Feb 18, 2014 by yamini.v

1 answer

The EMF of cell Hg/mercurous nitrate (0.01M)$\parallel$ mercurous nitrate (0.1M)/Hg was found to be 0.0295V at $25^{\large\circ}C$ .Then molecular formula of mercurous nitrate is

asked Feb 18, 2014 by sreemathi.v

1 answer

From following molar conductivities at infinite dilution $\Lambda_m^{\large\circ}$ for $Ba(OH)_2=457.6\Omega^{-1}cm^2mol^{-1}$,$\Lambda_m^{\large\circ}$ for $BaCl_2=240.6\Omega^{-1}cm^2mol^{-1}$,$\Lambda_m^{\large\circ}$ for $NH_4Cl=129.8\Omega^{-1}cm^2mol^{-1}$.The $\Lambda_m^{\large\circ}$ for $NH_4OH$ is

asked Feb 18, 2014 by sreemathi.v

1 answer

Calculate EMF of concentration cell consisting of zinc electrodes,one immersed in a solution of 0.01M $Zn^{+2}$ ions and the other in a solution of 0.1M $Zn^{+2}$ ions at $25^{\large\circ}C$.The two solution are separated by a salt bridge

asked Feb 18, 2014 by sreemathi.v

1 answer

If the radius of $Cs^+$ is 169pm and that of $Cl^-$ is 181pm then find the co-ordination number of $Cs^+$

asked Feb 18, 2014 by sharmaaparna1

1 answer

How many number of atoms are there in a cube based unit cell having one atom each corner and two atoms on each body diagonal of cube ?

asked Feb 18, 2014 by sharmaaparna1

1 answer

The EMF of electrode -concentration cell $Zn-Hg(C_1)/Zn^{+2}(aq)/Zn-Hg(C_2)$ at $25^{\large\circ}C$ if the concentration of zinc amalgam are $C_1=2g$ per 100g of mercury and $C_2=1g$ per 100g of mercury.

asked Feb 18, 2014 by sreemathi.v

1 answer

The electric potential varries in space according to the relation V= 4x+3y . A particle of mass 1 kg starts from rest from point $\;(8 , 3.9 m )\;$ under the influence of this field . Find the velocity of the particle when it crosses the y - axis . The charge on the particle ic $\;+1 \mu C$ .

asked Feb 18, 2014 by yamini.v

1 answer

For the following galvanic cell the emf will be at $25^{\large\circ}C$.$Ag/AgCl(s),KCl(0.2M\parallel KBr(0.001M).AgBr(s)/Ag$.The solubility product of $AgCl$ & $AgBr$ are $2.8\times 10^{-10}$ and $3.3\times 10^{-13}$ respectively.

asked Feb 18, 2014 by sreemathi.v

1 answer

The standard reduction potential of $Ag^+/Ag$ electrode at 298K is 0.79V.$K_{sp}$ of Ag$^+$ is $8.7\times 10^{-17}$.Evaluate the standard reduction potential of $I^-/AgI/Ag$ electrode

asked Feb 18, 2014 by sreemathi.v

1 answer

The half potential of $Cl^{-1}(C_1)/AgCl/Ag$ electrode.Given the value of $E^0$ for $Ag^++e^-\rightarrow Ag$ and $K_{sp}$ of AgCl is

asked Feb 18, 2014 by sreemathi.v

1 answer

A particle of mass m and charge -Q is constrained to move along the axis of a ring of radius R .The ring carries a uniform charge density $\;+ \lambda\;$ along its length . Initially the particle is in the centre of the ring . Now it is displaced slightly along the axis of ring it's time period of oscillation is

asked Feb 18, 2014 by yamini.v

1 answer

The emf of cell $Zn/ZnCl_2(0.05mol\;dm^{-3})/Ag^+/AgCl(s)/Ag$ is 1.015V at 298K,the silver electrode being positive,while the temperature coefficient of its emf is $-0.00492VK^{-1}$.Write down the equation for reaction occuring when the cell is allowed to discharge and calculate changes in entropy (s) accompanying this reaction,at 298K?

asked Feb 18, 2014 by sreemathi.v

1 answer

The emf of cell $Zn/ZnCl_2(0.05mol\;dm^{-3})/Ag^+/AgCl(s)/Ag$ is 1.015V at 298K,the silver electrode being positive,while the temperature coefficient of its emf is $-0.00492VK^{-1}$.Write down the equation for reaction occuring when the cell is allowed to discharge and calculate changes in free energy(G)?

asked Feb 18, 2014 by sreemathi.v

1 answer

Two conducting concentric , hollow sphere A and B have radii a and b respectively with A inside B . Their common potentials is V . A is now given some charge such that its potential becomes zero . The potential of B will now be

asked Feb 18, 2014 by yamini.v

1 answer

Consider the relation,$2Ag^++Cd\rightarrow 2Ag+Cd^{+2}$ the standard electrode potentials for $Ag^+/Ag$ and $Cd^{+2}/Cd$ couples $0.8\;V$ and $0.04\;V$ respectively Then the emf of given reaction will be (if $[Cd^{+2}]=0.1M,[Ad^+]=1M)$

asked Feb 18, 2014 by sreemathi.v

1 answer

Consider the relation,$2Ag^++Cd\rightarrow 2Ag+Cd^{+2}$ the standard electrode potentials for $Ag^+/Ag$ and $Cd^{+2}/Cd$ couples 0.8V and 0.04V respectively.What is the standard potential for this reaction?

asked Feb 18, 2014 by sreemathi.v

1 answer

In a uniform electric field , the potential is $10\;V$ at the origin of coordinates and $8V$ at each of the points $(1 ,0 ,0) ,(0 , 1 ,0)\;and\;(0 ,0,1)\;.$ The potential at the point $\;(1 ,1 ,1)\;$ will be

asked Feb 18, 2014 by yamini.v

1 answer

An electric current is passed through two electrolytic cells connected in series.One containing a solution of silver nitrate and the other solution of $H_2SO_4$.What volume of oxygen measured at $25^{\large\circ}C$ and 750mm of Hg would be liberated from $H_2SO_4$ if $8\times 10^{22}$ ions of $Ag^+$ are deposited from the silver nitrate solution?

asked Feb 17, 2014 by sreemathi.v

1 answer

A moving charge produces

asked Feb 17, 2014 by thanvigandhi_1

1 answer

An electric current is passed through two electrolytic cells connected in series.One containing a solution of silver nitrate and the other solution of $H_2SO_4$.What volume of oxygen measured at $25^{\large\circ}C$ and 750mm of Hg would be liberated from $H_2SO_4$ if 1mole and of $Ag^+$ are deposited from silver nitrate solution?

asked Feb 17, 2014 by sreemathi.v

1 answer

In an electrolysis experiment electric current was passed for 5hr through two cells connected in series.The first cell contains gold salt and second contains $CuSO_4$ solution.9.83g of gold was deposited in first cell.The magnitude of current in amperes is :-

asked Feb 17, 2014 by sreemathi.v

1 answer

In an electrolysis experiment electric current was passed for 5hr through two cells connected in series.The first cell contains gold salt and second contains $CuSO_4$ solution.9.83g of gold was deposited in first cell.If the oxidation number of Au is +3,find the amount of copper deposited in second cell

asked Feb 17, 2014 by sreemathi.v

1 answer

A charged particle is moving along a magnetic field line. The magnetic force on the particle is

asked Feb 17, 2014 by thanvigandhi_1

1 answer

A charged particle is moving in a region of uniform magnetic field and a parallel uniform electric field. At some time the velocity of the particle is perpendicular to the magnetic field. The trajectory of the particle will be

asked Feb 17, 2014 by thanvigandhi_1

1 answer

The passage of a constant current through a dilute solution of sulfuric acid with platinum electrodes,for the resulted in liberation of 336ml of mixed hydrogen and oxygen ,reduced to S.T.P.Then the strength of current is

asked Feb 17, 2014 by sreemathi.v

1 answer

A charged particle is moving in a constant magnetic field and at some point it has its velocity vector making an acute angle with the magnetic field. The path of the particle will be

asked Feb 17, 2014 by thanvigandhi_1

1 answer

A positively charged particle projected towards north is deflected towards west by a magnetic field. The field may be

asked Feb 17, 2014 by thanvigandhi_1

1 answer

A charged particle is whirled on a horizontal flat table by attaching it to a string fixed at one point. If a magnetic field is switched on in the vertical direction, the tension in the string

asked Feb 17, 2014 by thanvigandhi_1

1 answer

$CuSO_4$ solution(250ml) was electrolysed using a platinum anode and a copper cathode.At constant current of 2mA was passed for 16 minutes.It was found that after electrolysis the absorbance of this solution was reduced to 50% of its original value.Then the concentration of copper sulphate in solution to begin with is

asked Feb 17, 2014 by sreemathi.v

1 answer

Which of the following particles will have minimum frequency of revolution when projected with the same velocity perpendicular to a constant magnetic field?

asked Feb 17, 2014 by thanvigandhi_1

1 answer

Which of the following particles will describe the smallest circle when projected with the same velocity perpendicular to a constant magnetic field?

asked Feb 17, 2014 by thanvigandhi_1

1 answer

Which of the following particles will experience maximum magnetic force when projected with the same velocity perpendicular to a constant magnetic field?

asked Feb 17, 2014 by thanvigandhi_1

1 answer

The standard reduction potential of $Cu^{+2}/Cu$ and $Ag^+/Ag$ electrode are 0.337 and 0.799Volt respectively for this positive emf galvanic cell,for what concentration of $Ag^+$ will be emf of cell at $25^{\large\circ}C$ be zero,if the concentration of $Cu^{+2}$ is 0.01M?

asked Feb 17, 2014 by sreemathi.v

1 answer

A zinc rod is placed in $0.1\;M$ solution of $ZnSO_4$ at $25^{\large\circ}$C.Assuming that the salt is dissociated to the extent of $95\%$ at this dilusion ,then the potential of electrode at this temperature.Given that $E^0_{Zn^{2+}/Zn}=0.76Volts$.

asked Feb 17, 2014 by sreemathi.v

1 answer

A solution of a salt of a metal of atomic weight $'\lambda'$ was electrolysed for 150minutes with 0.15A of current .The weight of metal deposited was 0.783g.Find X,the specific heat of metal=0.057Cal/$g^{\large\circ}C$.According to Dulong-Petit's law,approximate atomic weight of a metal $X$ specific heat=6.4

asked Feb 17, 2014 by sreemathi.v

1 answer

Ask Questions, Get Answers