The enthalpy of neutralisation of \(\mathrm{HCl}\) and \(\mathrm{NaOH}\) is \(x \mathrm{~kJ}\). The heat evolved, when \(500 \mathrm{~mL}\) of \(2 \mathrm{~N} \mathrm{HCl}\) is mixed with \(250 \mathrm{~mL}\) of \(4 \mathrm{~N} \mathrm{NaOH}\) will be

What would be the volume of water required to dissolve \(0.2 \mathrm{~g}\) of \(\mathrm{PbCl}_2\) of molar mass \(278 \mathrm{~g} / \mathrm{mol}\) to prepare a saturated solution of the salt? \((\mathrm{K}_{\mathrm{SP}}\) of \(\mathrm{PbCl}_2=3.2 \times 10^{-8})\)

Given below are 2 statements: one Assertion and the other Reason. Which one of the following options is correct?
Assertion: Sulphur dioxide and Hydrogen peroxide can act as both oxidising and reducing agents but Nitric acid can act as only oxidising agent.
Reason: Sulphur and Oxygen can exhibit more than one stable oxidation states while Nitrogen does not.

The ratio of the difference between the radii of \(3^{\text {rd }}\) and \(4^{\text {th }}\) orbits of the \(\mathrm{He}^{+}\)and those of \(\mathrm{Li}^{2+}\) is:

The first fraction obtained during the fractionation of petroleum is

A statement of Assertion followed by a statement of Reason is given.
Choose the correct answer out of the following options.
Assertion : Energy of \(2 \mathrm{~s}\) orbital of Hydrogen is less than the energy of the \(2 \mathrm{~s}\) orbital of Lithium.
Reason : Energies of orbitals in the same subshell decrease with increase in atomic number.

Which one of the following structures in Column I does not have the correct IUPAC name as given in Column II.
\(\begin{array}{|c|l|l|} \hline \text { S.No. } & \text { Structure } & \text { IUPAC name. } \\ \hline \text { A } & {\left[\mathrm{CoBr} r_2(\mathrm{en})_2\right] \mathrm{Cl}} & \text { Dibromidodi-( ethan-1, 2 - diamine)cobalt (III) chloride } \\ \hline \text { B } & \mathrm{Na}\left[\mathrm{PtBrCl}\left(\mathrm{NO}_2\right)\left(\mathrm{NH}_3\right)\right] & \text { Sodium amminebromidochloridonitrito- N- palatinate(II) } \\ \hline \text { C } & {\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_2\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}\right] \mathrm{SO}_4} & \text { Tetraamminediaquachloridochromium (III) sulphate. } \\ \hline \text { D } & {\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_4\right]\left[\mathrm{PtCl}_4\right]} & \text { Tetraammineplatinum (II) tetrachloridoplatinate (II) } \\ \hline \end{array}\)

The complex number \(\frac{(-\sqrt{3}+3 i)(1-i)}{(3+\sqrt{3} i)(i)(\sqrt{3}+\sqrt{3} i)}\), when represented in the Argand diagram lies

A convex lens forms a real image of an object with magnification \(m_1\). The lens is moved towards the object to obtain another real image of magnification \(\mathrm{m}_2\). The image distance is increased by x . The focal length of the lens is

If \(A=\left[\begin{array}{lll}2 & 1 & 3 \\ 3 & 1 & 2 \\ 1 & 2 & 3\end{array}\right]\) and I is an identity by matrix of order \(3 \times 3\) then \(A(\operatorname{adj} A)=\)

Two charged spheres of \(-20 \mu \mathrm{C}\) and \(60 \mu \mathrm{C}\) are kept at a certain distance. They are touched and kept again at the same distance. What is the ratio of force experienced before and after?

If \(a\) and \(b\) are unit vectors and \(\mid\) a \(+b \mid=1\), then \(\mid\) a \(-b \mid\) is equal to

A charged particle is released from rest in a region of space in which steady and uniform electric and magnetic fields are parallel to each other. The particle will move in a