21.

Which one of the following electrolytes is used in Down's process of extracting sodium metal?

• NaCl + KCl + KF

• NaCl

• NaOH + KCl +KF

• NaCl + NaOH

Compound X is anhydride of sulphuric acid. The number of σ-bonds and the number of π-bonds presentin X are, respectively :

• 3,3

• 4,2

• 2,4

• 4,3

During the electrolysis of cryolite, aluminium and fluorine are formed in ...... molar ratio :

• 1:2

• 2:3

• 1:1

• 1:3

Ferrous ion charges to X ion, on reacting with acidified hydrogen peroxide. The number of d-electrons present in X and its magnetic moment (in BM) are, respectively :

• 6 and 6.93

• 5 and 5.92

• 5 and 4.9

• 4 and 5.92

The oxidation state of Xe in XeO₃ and the bond angle in it respectively are:

• +6, 109°

• +8, 103°

• +6, 103°

• +8, 120°

The product obtained at anode when 50% H₂SO₄ aqueous solution is electrolysed using platinum electrodes is :

• H₂SO₃

• H₂S₂O₈

• O₂

• H₂

Which one of the following equations represents Freundlich adsorption isotherm ?

• $\frac{\mathrm{x}}{\mathrm{m}}= \mathrm{Kp}$

• $\frac{\mathrm{x}}{\mathrm{m}}= {\mathrm{Kp}}^{\mathrm{n}}$

• $\log \frac{\mathrm{x}}{\mathrm{m}}= {\mathrm{Kp}}^{\mathrm{n}}$

• $\log \frac{\mathrm{x}}{\mathrm{m}}= \mathrm{Kn} \log \mathrm{p}$

Two oxides of nitrogen, NO and NO₂ react together at 253K and form a compound of nitrogen X. X reacts with water to yield another compound of nitrogen Y. The shape of the anion of Y molecule is :

• tetrahedral

• triangular planar

• square planar

• pyramidal

Chlorine atom, in its third excited state, reacts with fluorine to form a compound X. The formula and shape of X are :

• ClF₅,  pentagonal

• ClF₄, tetrahedral

• ClF₄, pentagonal bipyramidal

• ClF₇, pentagonal bipyramidal

If the mass defect of a nuclide is 3.32 x 10^-26g, its binding energy is ......... MeV

• 9.31

• 18.62

• 27.93

• 37.24