In the electrothermal process, the compound displaced by silica from calcium phosphate is

Choose the correct metal/ ion from the brackets which ..........
A. has chemical reactivity similar to that of the first few members of the Lanthanoids \((\mathrm{Zn}, \mathrm{Ca}, \mathrm{Fe}, \mathrm{Cu})\).
B. has stable \(4 \mathrm{f}^7\) electronic configuration, but acts as a strong reducing agent and converts to \(\mathrm{M}^{3+}\) state. \(\left(\mathrm{Eu}^{2+}, \mathrm{Ce}^{2+}, \mathrm{Pr}^{2+}, \mathrm{Dy}^{2+}\right)\)
C. is a colorless ion \(\left(\mathrm{Tm}^{3+}, \mathrm{Lu}^{3+}, \mathrm{Gd}^{3+}, \mathrm{Sm}^{3+}\right)\).
D. shows stable +2 oxidation state and is diamagnetic \((\mathrm{Ce}, \mathrm{Sm}, \mathrm{Ho}, \mathrm{Yb})\)

The first fraction obtained during the fractionation of petroleum is

Which of the following species do not show disproportionation reaction?

In the manufacture of sulphuric acid by contact process, Tyndall box is used to

Which defect leads to decrease in the density of crystal?

From the given covalent compounds (A to F) identify the pair of molecules which have:
(i) Two lone pairs of electrons on the central atom.
(ii) One lone pair of electrons on the central atom.
A. \(\mathrm{SO}_2\)
B. \(\mathrm{ClF}_3\)
C. \(\mathrm{BF}_3\)
D. \(\mathrm{BrF}_5\)
E. \(\mathrm{XeF}_4\)
F. \(\mathrm{SF}_6\)

The current drawn from the battery by the network of resistors as shown in the figure is

One among the 4 Vitamins belonging to \(\mathrm{B}\) Complex, can be stored in our body. Identify the Vitamin.

Which type of ligand is EDTA?

Which cycloalkane has the lowest heat of combustion per \(\mathrm{CH}_{2}\) group?

The distance between the point \((1,2)\) from the line \(3 x+4 y=6\) measured parallel to the line \(3 x-4 y=5\).

Which of the following electrolytic solution has the least specific conductance?