On an X-ray diffraction photograph the intensity of the spots depends on:

• neutron density of the atoms/ions

• electron density of the atoms/ions

• proton density of the atoms/ions

• photon density of the atoms/ions

The standard reduction potentials at 298 K for the following half reactions are given against each:

$$\begin{gathered} {\mathrm{Zn}}^{+}\left(\mathrm{aq}\right) +2{\mathrm{e}}^{-}\to \mathrm{Zn}\left(\mathrm{s}\right) {\mathrm{E}}^{°} = - 0.762 \mathrm{V} \\ {\mathrm{Cr}}^{3+} \left(\mathrm{aq}\right) + 3{\mathrm{e}}^{-} \to \mathrm{Cr}\left(\mathrm{s}\right) {\mathrm{E}}^{°} = - 0.7420\mathrm{V} \\ 2{\mathrm{H}}^{+}\left(\mathrm{aq}\right) + 2{\mathrm{e}}^{-} \to {\mathrm{H}}_2\left(\mathrm{g}\right) {\mathrm{E}}^{°} = 0.00\mathrm{V} \\ {\mathrm{Fe}}^{3+}\left(\mathrm{aq}\right) + 3{\mathrm{e}}^{-} \to {\mathrm{Fe}}^{2+ }{\mathrm{E}}^{°} =+ 0.762 \mathrm{V} \end{gathered}$$

The strongest reducing agents is:

• Zn(s)

• Cr(s)

• H₂ (g)

• Fe²⁺ (aq)

In which of the below reaction do we find $\mathrm{\alpha },\mathrm{\beta }-$unsaturated carbonyl compounds undergoing a ring closure reaction with conjugated dienes?

• Perkin reaction

• Diels-Alder reaction

• Claisen rearrangement

• Hofmann reaction

Identify, which of the below does not possess any element of symmetry?

• (+) and (-) tartaric acid

• Carbon tetrachlorid

• Methane

• Meso- tartaric acid

An ion leaves its regular site occupy a position in the space between the lattice sites is called

• Frenkel defect

• Schottky defect

• impurity defect

• vacancy defect

The 8: 8 type of packing is present in

• MgF₂

• CsCl

• KCl

• NaCl

According to Arrhenius equation, the rate constant (K) is related to temperature (T) as

• $\ln \frac{{\mathrm{K}}_2 }{{\mathrm{K}}_2 }= \frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}\left[\frac{1}{{\mathrm{T}}_1}-\frac{1}{{\mathrm{T}}_2}\right]$

• $\ln \frac{{\mathrm{K}}_2 }{{\mathrm{K}}_2 }= -\frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}\left[\frac{1}{{\mathrm{T}}_1}-\frac{1}{{\mathrm{T}}_2}\right]$

• $\ln \frac{{\mathrm{K}}_2 }{{\mathrm{K}}_2 }= \frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}\left[\frac{1}{{\mathrm{T}}_1}+\frac{1}{{\mathrm{T}}_2}\right]$

• $\ln \frac{{\mathrm{K}}_2 }{{\mathrm{K}}_2 }= - \frac{{\mathrm{E}}_{\mathrm{a}}}{\mathrm{R}}\left[\frac{1}{{\mathrm{T}}_1}+\frac{1}{{\mathrm{T}}_2}\right]$

How long (in hours) must a current of 5.0 A be maintained to electroplate 60 g of calcium from molten CaCl₂ ?

• 27 h

• 8.3 h

• 11 h

• 16 h

19.

For strong electrolytes the plot of molar conductance vs $\sqrt{\mathrm{C}}$ is

• parabolic

• linear

• sinusoidal

• circular

If the molar conductance values of Ca²⁺ and Cl^- at infinite dilution are respectively 118.88 X 10^-4 m² $\mathrm{\Omega }$ho mol^-1 and 77.33 X 10^-4m² $\mathrm{\Omega }$ho mol^-1 then that of CaCl₂ is ( in m² $\mathrm{\Omega }$ho mol^-1): 

• 118.88 X 10^-4

• 154.66  X 10^-4

• 273.54  X 10^-4

• 196.21 X 10^-4