An aqueous solution of \(\mathrm{NiCl}_{2}\) was heated with excess sodium cyanide in presence of strong oxidizing agent to form \(\left[\mathrm{Ni}(\mathrm{CN})_{6}\right]^{2-}\). The total change in number of unpaired electrons on metal centre is \(.....\)

A solution containing \(10 \mathrm{~g}\) of an electrolyte \(\mathrm{AB}_2\) in \(100 \mathrm{~g}\) of water boils at \(100.52^{\circ} \mathrm{C}\). The degree of ionization of the electrolyte \((\alpha)\) is _______ \(\times 10^{-1}\). (nearest integer) [Given : Molar mass of \(\mathrm{AB}_2=200 \mathrm{~g} \mathrm{~mol}^{-1} \cdot \mathrm{K}_{\mathrm{b}}\) (molal boiling point elevation const. of water) \(=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\), boiling point of water \(=100^{\circ} \mathrm{C}\); \(\mathrm{AB}_2\) ionises as \(\left.\mathrm{AB}_2 \rightarrow \mathrm{A}^{2+}+2 \mathrm{~B}^{-}\right]\)

Which of these factors does not govern the stability of a conformation in acyclic compounds?

In the reaction,
\(2Al(s)+6HCl(aq)\rightarrow2Al^{3+}(aq)+6Cl^{-}(aq)+3H_{2}(g)\)

In comparison to boron, berylium has

Given below are two statements: One is labelled as Assertion (\(A\)) and the other is labelled as Reason (\(R\)). Assertion (\(A\)): Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always \(-57 \mathrm{~kJ} \mathrm{~mol}^{-1}\) Reason (\(R\)): Enthalpy of neutralisation is the amount of heat liberated when one mole of \(\mathrm{H}^{+}\)ions furnished by acid combine with one mole of \({ }^{-} \mathrm{OH}\) ions furnished by base to form one mole of water.
In the light of the above statements, choose the correct answer from the options given below.

A chloro compound \("A".\) \((i)\) forms aldehydes on ozonolysis followed by the hydrolysis. \((ii)\) when vaporized completely \(1.53\, \mathrm{~g}\) of \(\mathrm{A}\), gives \(448\, \mathrm{~mL}\) of vapour at \(STP.\) The number of carbon atoms in a molecule of compound \(A\) is ...... .

Chloro compound of Vanadium has only spin magnetic moment of \(1.73\, BM\). This Vanadium chloride has the formula

The area enclosed by the curves \(y^2+4 x=4\) and \(y-2 x=2\) is :

A ball of mass \(10\, kg\) moving with a velocity \(10 \sqrt{3} m / s\) along the \(x-\)axis, hits another ball of mass \(20\, kg\) which is at rest. After the collision, first ball comes to rest while the second ball disintegrates into two equal pieces. One piece starts moving along \(y-\)axis with a speed of \(10\) \(m / s\). The second piece starts moving at an angle of \(30^{\circ}\) with respect to the \(x-\)axis. The velocity of the ball moving at \(30^{\circ}\) with \(x-\) axis is \(x\, m / s\). The configuration of pieces after collision is shown in the figure below. The value of \(x\) to the nearest integer is

Two engines pass each other moving in opposite directions with uniform speed of \(30\,m/s\) . One of them is blowing a whistle of frequency \(540\,Hz.\) Calculate the frequency heard by driver of second engine before they pass each other  ... \(Hz\). Speed of sound is \(330\,m/sec\)

A pendulum is executing simple harmonic motion and its maximum kinetic energy is \(K_1\). If the length of the pendulum is doubled and it performs simple harmonic motion with the same amplitude as in the first case, its maximum kinetic energy is \(K_2\) then

The magnetic field in a plane electromagnetic wave is \(\mathrm{B}_y=\left(3.5 \times 10^{-7}\right) \sin \left(1.5 \times 10^3 \mathrm{x}+0.5\right.\) \(\left.\times 10^{11} \mathrm{t}\right) \mathrm{T}\). The corresponding electric field will be _______.