The concentration of electrolyte required to coagulate a given amount of \(\mathrm{As}_{2} \mathrm{S}_{3}\) sol is minimum in the case of

The equivalent weight of a certain trivalent element is \(20\). Molecular weight of its oxide is

Match the reactions in Column I with the correct products given in Column II:
\(\begin{array}{|l|l|l|l|} \hline \text{S.N.} & \text{Column I} & \text{S.No.} & \text{Column II} \\ \hline \text{A} & 1- \text{Chloropropane} + (\mathrm{Zn} / \mathrm{HCl}) \rightarrow & \text{P} & \text{Propanone + Methanal} \\ \hline \text{B} & n- \text{Hexane + (anh.} \left.\mathrm{AlCl}_3 / \mathrm{HCl}_{(\mathrm{g})}\right) \rightarrow & \text{Q} & \text{Propanone} \\ \hline \text{C} & 2- \text{Methylpropene} + ( \left.\mathrm{O}_3 ~\&~ \mathrm{Zn} / \mathrm{H}_2 \mathrm{O}\right) \rightarrow & \text{R} & \text{Propane} \\ \hline \text{D} & \text{Propyne} +\left(\mathrm{HgSO}_4 / \mathrm{H}_2 \mathrm{SO}_4\right. at 333 K) \rightarrow & \text{S} & \text{2-Methylpentane + 3-Methylpentane} \\ \hline \end{array}\)

0.60 g of urea is dissolved in 360 g of water at room temperature. The vapour pressure of pure water is 35 mm of Hg , the lowering of vapour pressure at this temperature is:
[Molar mass of urea is \(60 \mathrm{~g} \mathrm{~mol}^{-1}\) ]

A crystalline solid has \(A^{-}\)ions at the corners and face centres, whereas \(B^{+}\)ions are at the body centre and edge centres of the unit cell. The simplest formula of the compound will be

The number of disulphide linkages present in insulin are

\(\text{K}_2\text{Cr}_2\text{O}_7\) on heating with aqueous NaOH gives -------------------------

The initial amount of 2 radioactive elements X and Y is 1 g each and their half-lives are 12 hours and 16 hours respectively. The ratio of X and Y after 2 days is:

During the phenomenon of resonance

The ratio of the angle of deviation produced by a thin prism, when it is placed in air to the angle of deviation produced when it is immersed in water of refractive index \(\dfrac{4}{3}\) is:

If \(\cot ^{-1} \frac{1}{5}+\cot ^{-1} \frac{1}{3}-\cot ^{-1} \frac{4}{7}=\cot ^{-1} x\), then \(x\) is equal to

The wavelength of the radiation emitted by a body depends upon

Which of the following compound does not exists?