The standard enthalpy of formation $$\Delta _fH^o$$ at 298 K for methane, CH4(g), is –74.8 kJ mol–1. The additional info

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If Ti is the initial temperatu

The enthalpy changes for the following processes are listed below : Cl2(g) = 2Cl(g), 242.3 kJ mol–1 I2(g) = 2I(g), 151

($$\Delta H - \Delta U$$) for the formation of carbon monoxide (CO) from its elements at 298 K is : (R = 8.314 J K–1 mol

Phosphorus pentachloride dissociates as follows, in a closed reaction vessel PCl5 (g) $$\leftrightharpoons$$ PCl3 (g) +

The equilibrium constant for the reaction SO3 (g) $$\leftrightharpoons$$ SO2 (g) + $$1 \over 2$$ O2 (g) is Kc = 4.9 $$

Given the data at 25oC, Ag + I- $$\to$$ AgI + e- , Eo = 0.152 V Ag $$\to$$ Ag+ + e-, Eo = -0.800 V What is the value of

CH3Br + Nu- $$\to$$ CH3 - Nu + Br- The decreasing order of the rate of the above reaction with nucleophiles (Nu–) A to D

The increasing order of stability of the following free radicals is

Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2-fluoroethanol is

How many EDTA (ethylenediaminetetraacetic acid) molecules are required to make an octahedral complex with a Ca2+ ion?

Fluorobenzene (C6H5F) can be synthesized in the laboratory

Phenyl magnesium bromide reacts with methanol to give

Reaction of trans-2-phenyl-1-bromocyclopentane on reaction with alcoholic KOH produces

HBr reacts with CH2 = CH – OCH3 under anhydrous conditions at room temperature to give

The increasing order of the rate of HCN addition to compounds A – D is (A) HCHO (B) CH3COCH3 (C) PhCOCH3 (D) PhCOPh

The term anomers of glucose refers to

The pyrimidine bases present in DNA are

In Fe(CO)5, the Fe – C bond possesses :

The $$IUPAC$$ name of the compound shown below is :

The alkene formed as a major product in the above elimination reaction is

The structure of the major product formed in the following reaction is

The structure of the compound that gives a tribromo derivative on treatment with bromine water is

The electrophile involved in the above reaction is

Among the following the one that gives positives iodoform test upon reaction with $${I_2}$$ and $$NaOH$$ is

The correct order of increasing acid strength of the compounds

A metal, $$M$$ forms chlorides in its $$+2$$ and $$+4$$ oxidation states. Which of the following statements about these

In the transformation of $${}_{92}^{238}U$$ to $${}_{92}^{234}U$$, if one emission is an α-particle, what should be the

Among the following mixtures, dipole-dipole as the major interaction, is present in

18 g of glucose (C6H12O6) is added to 178.2 g of water. The vapour pressure of water for this aqueous solution at 100oC

Which of the following chemical reactions depicts the oxidizing behaviour of H2SO4?

The molar conductivities $$ \wedge _{NaOAc}^o$$ and $$ \wedge _{HCl}^o$$ and at infinite dilution in water at 25oC are

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100$$\Omega $$. The

Rate of a reaction can be expressed by Arrhenius equation as: $$$k = A\,{e^{ - E/RT}}$$$ In this equation, E represents

A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of ca

The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr: NO(g) + Br2 (g) $$\leftrighthar

The increasing order of the first ionization enthalpies of the elements B, P, S and F (lowest first) is :

Which of the following statements is true?

The “spin-only” magnetic moment [in units of Bohr magneton, (µB)] of Ni2+ in aqueous solution would be : (Atomic number

Lanthanoid contraction is caused due to :

Nickel (Z = 28) combines with a uninegative monodentate ligand X– to form a paramagnetic complex [NiX4]2− . The number o

The IUPAC name for the complex [Co(NO2)(NH3)5]Cl2 is

How many moles of magnesium phosphate Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?

Density of a 2.05M solution of acetic acid in water is 1.02 g/mL The molality of the solution is

Uncertainty in the position of an electron (mass = 9.1 $$\times$$ 10-31 kg) moving with a velocity 300 ms-1, accurate up

According to Bohr's theory, the angular momentum of an electron in 5th orbit is

Which of the following sets of ions represents a collection of isoelectronic species?

Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are give

Which of the following molecules/ions does not contain unpaired electrons?

In which of the following molecules/ions are all the bonds not equal?

The decreasing values of bond angles from NH3 (106o) to SbH3 (91o ) down group-15 of the periodic table is due to

Suppose a population A has 100 observations 101, 102,........, 200, and another population B has 100 observations 151, 1

The value of $$\int\limits_1^a {\left[ x \right]} f'\left( x \right)dx,a > 1$$ where $${\left[ x \right]}$$ denotes t

The set of points where $$f\left( x \right) = {x \over {1 + \left| x \right|}}$$ is differentiable is

If $${x^m}.{y^n} = {\left( {x + y} \right)^{m + n}},$$ then $${{{dy} \over {dx}}}$$ is

The function $$f\left( x \right) = {x \over 2} + {2 \over x}$$ has a local minimum at

A triangular park is enclosed on two sides by a fence and on the third side by a straight river bank. The two sides havi

If $$A$$ and $$B$$ are square matrices of size $$n\, \times \,n$$ such that $${A^2} - {B^2} = \left( {A - B} \right)\le

Let $$A = \left( {\matrix{ 1 & 2 \cr 3 & 4 \cr } } \right)$$ and $$B = \left( {\matrix{ a & 0

$$\int\limits_0^\pi {xf\left( {\sin x} \right)dx} $$ is equal to

$$\int\limits_{ - {{3\pi } \over 2}}^{ - {\pi \over 2}} {\left[ {{{\left( {x + \pi } \right)}^3} + {{\cos }^2}\left( {x

The differential equation whose solution is $$A{x^2} + B{y^2} = 1$$ where $$A$$ and $$B$$ are arbitrary constants is of

At a telephone enquiry system the number of phone cells regarding relevant enquiry follow Poisson distribution with an a

The values of a, for which the points $$A, B, C$$ with position vectors $$2\widehat i - \widehat j + \widehat k,\,\,\wi

The two lines $$x=ay+b, z=cy+d;$$ and $$x=a'y+b' ,$$ $$z=c'y+d'$$ are perpendicular to each other if :

If $$0 < x < \pi $$ and $$\cos x + \sin x = {1 \over 2},$$ then $$\tan x$$ is :

If $${z^2} + z + 1 = 0$$, where z is complex number, then value of $${\left( {z + {1 \over z}} \right)^2} + {\left( {{z^

The value of $$\sum\limits_{k = 1}^{10} {\left( {\sin {{2k\pi } \over {11}} + i\,\,\cos {{2k\pi } \over {11}}} \right)}

If the roots of the quadratic equation $${x^2} + px + q = 0$$ are $$\tan {30^ \circ }$$ and $$\tan {15^ \circ }$$, respe

All the values of $$m$$ for which both roots of the equation $${x^2} - 2mx + {m^2} - 1 = 0$$ are greater than $$ - 2$$ b

If $$x$$ is real, the maximum value of $${{3{x^2} + 9x + 17} \over {3{x^2} + 9x + 7}}$$ is

At an election, a voter may vote for any number of candidates, not greater than the number to be elected. There are 10 c

If the expansion in powers of $$x$$ of the function $${1 \over {\left( {1 - ax} \right)\left( {1 - bx} \right)}}$$ is $$

If $${{a_1},{a_2},....{a_n}}$$ are in H.P., then the expression $${{a_1}\,{a_2} + \,{a_2}\,{a_3}\, + .... + {a_{n - 1}}\

Let $${a_1}$$, $${a_2}$$, $${a_3}$$.....be terms on A.P. If $${{{a_1} + {a_2} + .....{a_p}} \over {{a_1} + {a_2} + .....

A straight line through the point $$A (3, 4)$$ is such that its intercept between the axes is bisected at $$A$$. Its equ

If $$\left( {a,{a^2}} \right)$$ falls inside the angle made by the lines $$y = {x \over 2},$$ $$x > 0$$ and $$y = 3x,

If the lines $$3x - 4y - 7 = 0$$ and $$2x - 3y - 5 = 0$$ are two diameters of a circle of area $$49\pi $$ square units,

Let $$C$$ be the circle with centre $$(0, 0)$$ and radius $$3$$ units. The equation of the locus of the mid points of th

In the ellipse, the distance between its foci is $$6$$ and minor axis is $$8$$. Then its eccentricity is :

The locus of the vertices of the family of parabolas $$y = {{{a^3}{x^2}} \over 3} + {{{a^2}x} \over 2} - 2a$$ is :

Let $W$ denote the words in the English dictionary. Define the relation $R$ by $R=\{(x, y) \in W \times W \mid$ the wor

The $$rms$$ value of the electric field of the light coming from the Sun is $$720$$ $$N/C.$$ The average total energy de

The circuit has two oppositively connected ideal diodes in parallel. What is the current following in the circuit?

In the following, which one of the diodes is reverse biased?

The anode voltage of a photocell is kept fixed. The wavelength $$\lambda $$ of the light falling on the cathode is gradu

If the lattice constant of this semiconductor is decreased, then which of the following is correct?

An inductor $$(L=100$$ $$mH)$$, a resistor $$\left( {R = 100\,\Omega } \right)$$ and a battery $$\left( {E = 100V} \righ

Needles $${N_1}$$, $${N_2}$$ and $${N_3}$$ are made of ferromagnetic, a paramagnetic and a diamagnetic substance respect

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A

A long solenoid has $$200$$ turns per $$cm$$ and carries a current $$i.$$ The magnetic field at its center is $$6.28 \ti

Which of the following units denotes the dimension $${{M{L^2}} \over {{Q^2}}}$$, where $$Q$$ denotes the electric charge

In a series resonant $$LCR$$ circuit, the voltage across $$R$$ is $$100$$ volts and $$R = 1\,k\Omega $$ with $$C = 2\mu

In an $$AC$$ generator, a coil with $$N$$ turns, all of the same area $$A$$ and total resistance $$R,$$ rotates with fre

The flux linked with a coil at any instant $$'t'$$ is given by $$\phi = 10{t^2} - 50t + 250$$ The induced $$emf$$ at

The refractive index of a glass is $$1.520$$ for red light and $$1.525$$ for blue light. Let $${D_1}$$ and $${D_2}$$ be

The threshold frequency for a metallic surface corresponds to an energy of $$6.2$$ $$eV$$ and the stopping potential for

The time taken by a photoelectron to come out after the photon strikes is approximately

An alpha nucleus of energy $${1 \over 2}m{v^2}$$ bombards a heavy nuclear target of charge $$Ze$$. Then the distance of

If the ratio of the concentration of electrons to that of holes in a semiconductor is $${7 \over 5}$$ and the ratio of c

A solid which is not transparent to visible light and whose conductivity increases with temperature is formed by

When $${}_3L{i^7}$$ nuclei are bombarded by protons, and the resultant nuclei are $${}_4B{e^8}$$, the emitted particles

If the binding energy per nucleon in $${}_3^7Li$$ and $${}_2^4He$$ nuclei are $$5.60$$ $$MeV$$ and $$7.06$$ $$MeV$$ resp

The resistance of bulb filmanet is $$100\Omega $$ at a temperature of $${100^ \circ }C.$$ If its temperature coefficient

If the terminal speed of a sphere of gold (density $$ = 19.5\,\,kg/{m^3}$$) is $$0.2$$ $$m/s$$ in a viscous liquid (dens

A wire elongates by $$l$$ $$mm$$ when a LOAD $$W$$ is hanged from it. If the wire goes over a pulley and two weights $$W

The work of $$146$$ $$kJ$$ is performed in order to compress one kilo mole of gas adiabatically and in this process the

Assuming the Sun to be a spherical body of radius $$R$$ at a temperature of $$TK$$, evaluate the total radiant powered i

Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperatu

A force of $$ - F\widehat k$$ acts on $$O,$$ the origin of the coordinate system. The torque about the point $$(1, -1)$

Starting from the origin a body oscillates simple harmonically with a period of $$2$$ $$s.$$ After what time will its ki

The maximum velocity of a particle, executing simple harmonic motion with an amplitude $$7$$ $$mm,$$ is $$4.4$$ $$m/s.$$

A string is stretched between fixed points separated by $$75.0$$ $$cm.$$ It is observed to have resonant frequencies of

An electric dipole is placed at an angle of $${30^ \circ }$$ to a non-uniform electric field. The dipole will experience

Two spherical conductors $$A$$ and $$B$$ of radii $$1$$ $$mm$$ and $$2$$ $$mm$$ are separated by a distance of $$5$$ $$c

Two insulating plates are both uniformly charged in such a way that the potential difference between them is $${V_2} - {

A thermocouple is made from two metals, Antimony and Bismuth. If one junction of the couple is kept hot and the other is

An electric bulb is rated $$220$$ volt - $$100$$ watt. The power consumed by it when operated on $$110$$ volt will be

In a Wheatstone's bridge, three resistance $$P, Q$$ and $$R$$ connected in the three arms and the fourth arm is formed b

The current $${\rm I}$$ drawn from the $$5$$ volt source will be

Four point masses, each of value $$m,$$ are placed at the corners of a square $$ABCD$$ of side $$l$$. The moment of iner

A particle located at x = 0 at time t = 0, starts moving along the positive x-direction with a velocity 'v' that varies

A mass of $$M$$ $$kg$$ is suspended by a weightless string. The horizontal force that is required to displace it until t

A ball of mass $$0.2$$ $$kg$$ is thrown vertically upwards by applying a force by hand. If the hand moves $$0.2$$ $$m$$

A player caught a cricket ball of mass $$150$$ $$g$$ moving at a rate of $$20$$ $$m/s.$$ If the catching process is com

A coin is placed on a horizontal platform which undergoes vertical simple harmonic motoin of angular frequency $$\omega

A particle of mass $$100g$$ is thrown vertically upwards with a speed of $$5$$ $$m/s$$. The work done by the force of gr

The potential energy of a $$1$$ $$kg$$ particle free to move along the $$x$$-axis is given by $$V\left( x \right) = \lef

A bomb of mass $$16kg$$ at rest explodes into two pieces of masses $$4$$ $$kg$$ and $$12$$ $$kg.$$ The velocity of the $

Consider a two particle system with particles having masses $${m_1}$$ and $${m_2}$$. If the first particle is pushed tow

A thin circular ring of mass $$m$$ and radius $$R$$ is rotating about its axis with a constant angular velocity $$\omega