Surface Chemistry & Solid State · JEE Advanced previous year questions

The density (in $\mathrm{g}\mathrm{c}{\mathrm{m}}^{-3}$) of the metal which forms a cubic close packed (ccp) lattice with an axial distance (edge length) equal to $400\text{ pm}$ is _________. $\text{Use:}$ Atomic mass of metal $=105.6\text{ amu}$ and Avogadro's constant $=6\times 10^{23}{\text{ mol}}^{-1}$

Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm. At a given temperature, from $10{\text{ mg g}}^{-1}$ and $16{\text{ mg g}}^{-1}$ aqueous phenol solutions, the concentrations of adsorbed phenol are measured to be $4{\text{ mg g}}^{-1}$ and $10{\text{ mg g}}^{-1}$, respectively. At this temperature, the concentration (in ${\text{mg g}}^{-1}$) of adsorbed phenol from $20{\text{ mg g}}^{-1}$ aqueous solution of phenol will be _________. $\text{Use:}$ ${\log }_{10}2=0.3$

1. A.i) Lindlar’s catalyst, ${\mathrm{H}}_2$; ii) $\mathrm{SnC}{\mathrm{l}}_2/HCl$; iii) $\mathrm{NaB}{\mathrm{H}}_4$; iv) ${\mathrm{H}}_3{\mathrm{O}}^{+}$
2. B.i) Lindlar’s catalyst, ${\mathrm{H}}_2$; ii) ${\mathrm{H}}_3{\mathrm{O}}^{+}$; iii) $\mathrm{SnC}{\mathrm{l}}_2/HCl$; iv) $\mathrm{NaB}{\mathrm{H}}_4$
3. C.i) $\mathrm{NaB}{\mathrm{H}}_4$; ii) $\mathrm{SnC}{\mathrm{l}}_2/HCl$; iii) ${\mathrm{H}}_3{\mathrm{O}}^{+}$; iv) Lindlar’s catalyst, ${\mathrm{H}}_2$
4. D.i) Lindlar’s catalyst, ${\mathrm{H}}_2$; ii) $\mathrm{NaB}{\mathrm{H}}_4$; iii) $\mathrm{SnC}{\mathrm{l}}_2/HCl$; iv) ${\mathrm{H}}_3{\mathrm{O}}^{+}$

Consider the following statements related to colloids. (I) Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium. (II) For emulsions, both the dispersed phase and the dispersion medium are liquid. (III) Micelles are produced by dissolving a surfactant in any solvent at any temperature. (IV) Tyndall effect can be observed from a colloidal solution with dispersed phase having the same refractive index as that of the dispersion medium. The option with the correct set of statements is

1. A.(I) and (II)
2. B.(II) and (III)
3. C.(III) and (IV)
4. D.(II) and (IV)

Atoms of metals $\mathrm{x}$, $\mathrm{y}$, and $\mathrm{z}$ form face-centred cubic (fcc) unit cell of edge length ${\mathrm{L}}_{\mathrm{x}}$, body-centred cubic (bcc) unit cell of edge length ${\mathrm{L}}_{\mathrm{y}}$, and simple cubic unit cell of edge length ${\mathrm{L}}_{\mathrm{z}}$, respectively. If $r_{\mathrm{z}}=\frac{\sqrt{3}}{2}{r}_{\mathrm{y}}$ ; $r_{\mathrm{y}}=\frac{8}{\sqrt{3}}{r}_{\mathrm{x}}$ ; ${\mathrm{M}}_{\mathrm{z}}=\frac{3}{2}{\mathrm{M}}_{\mathrm{y}}$ and ${\mathrm{M}}_{\mathrm{z}}=3{\mathrm{M}}_{\mathrm{x}}$, then the correct statement(s) is(are) [Given: ${\mathrm{M}}_{\mathrm{x}}$, ${\mathrm{M}}_{\mathrm{y}}$, and ${\mathrm{M}}_{\mathrm{z}}$ are molar masses of metals $\mathrm{x}$, $\mathrm{y}$, and $\mathrm{z}$, respectively. $r_{\mathrm{x}}$, $r_{\mathrm{y}}$, and $r_{\mathrm{z}}$ are atomic radii of metals $\mathrm{x}$, $\mathrm{y}$, and $\mathrm{z}$, respectively.]

1. A.Packing efficiency of unit cell of $\mathrm{x}>$ Packing efficiency of unit cell of $\mathrm{y}>$ Packing efficiency of unit cell of $\mathrm{z}$
2. B.${\mathrm{L}}_{\mathrm{y}}>{\mathrm{L}}_{\mathrm{z}}$
3. C.${\mathrm{L}}_{\mathrm{x}}>{\mathrm{L}}_{\mathrm{y}}$
4. D.Density of $\mathrm{x}>$ Density of $\mathrm{y}$