The number of halobenzenes from the following that can be prepared by Sandmeyer's reaction is _______.

According to \(IUPAC\) system, the compound is named as _______.

What weight of glucose must be dissolved in \(100 g\) of water to lower the vapour pressure by \(0.20\, mm\) \(Hg\) ? (Assume dilute solution is being formed) Given: Vapour pressure of pure water is \(54.2\,mm\) \(Hg\) at room temperature. Molar mass of glucose is \(180\,g\,mol ^{-1}\)

Amongst the following alcohols which would react fastest with conc. \(HCl\) and \(ZnCl_2\) ?

\(\mathrm{A}(\mathrm{g}) \rightarrow \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})\) is a first order reaction.
\(\begin{array}{|l|l|l|}\hline \text{Time} & T & \infty \\\hline \mathbf{P}_{\text {system }} & \mathrm{P}_{\mathrm{t}} & \mathrm{P}_{\infty} \\\hline\end{array}\)
The reaction was started with reactant A only. Which of the following expression is correct for rate constant k ?

The pH of a 0.01 M weak acid \(\mathrm{HX}\left(\mathrm{K}_{\mathrm{a}}=4 \times 10^{-10}\right)\) is found to be 5. Now the acid solution is diluted with excess of water so that the pH of the solution changes to 6. The new concentration of the diluted weak acid is given as \(x \times 10^{-4} \mathrm{M}\). The value of x is ________ (nearest integer)

The mole fraction of a solvent in aqueous solution of a solute is \(0.8\). The molality (in \(mol\, kg^{-1}\)) of the aqueous solution is

The ratio of de-Broglie wavelength of an \(\alpha\)-particle and a proton accelerated from rest by the same potential is \(\frac{1}{\sqrt{ m }}\), the value of \(m\) is \(........\)

The optically inactive compound from the following is

Given below are two statements: one is labelled as Assertion \((A)\) and the other is labelled as Reason \((R)\). Assertion \((A)\) : \(\mathrm{NH}_3\) and \(\mathrm{NF}_3\) molecule have pyramidal shape with a lone pair of electrons on nitrogen atom. The resultant dipole moment of \(\mathrm{NH}_3\) is greater than that of \(\mathrm{NF}_3\). Reason \((R)\) : In \(\mathrm{NH}_3\), the orbital dipole due to lone pair is in the same direction as the resultant dipole moment of the \(\mathrm{N}-\mathrm{H}\) bonds. \(\mathrm{F}\) is the most electronegative element. In the light of the above statements, choose the correct answer from the options given below:

Surface tension of a soap bubble is \(2.0 \times 10^{-2}\; Nm ^{-1}\). Work done to increase the radius of soap bubble from \(3.5\; cm\) to \(7\; cm\) will be \(.........\times 10^{-4}\,J\) [Take \(\pi=\frac{22}{7}\) ]

A long, straight wire of radius \(a\) carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire at distance \(\frac{a}{3}\) and \(2 a,\) respectively from the axis of the wire is

Two planets \(A\) and \(B\) of equal mass are having their period of revolutions \(T_{A}\) and \(T_{B}\) such that \(T_{A}=2 T_{B}\). These planets are revolving in the circular orbits of radii \(I_{A}\) and \(I_{B}\) respectively. Which out of the following would be the correct relationship of their orbits?