Physical Chemistry PYQ — Page 17

The de-Broglie's wavelength of an electron in the \(4^{\text {th }}\) orbit is \(\qquad\) \(\pi \mathrm{a}_0 \cdot\left(\mathrm{a}_0=\right.\) Bohr's radius \()\)

Volume of $3M\mathrm{NaOH}$ (formula weight $40g{\mathrm{mol}}^{-1}$ ) which can be prepared from $84g$ of $\mathrm{NaOH}$ is ____$\times {10}^{-1}{\mathrm{dm}}^{3}$.

A solution of ${H}_{2}{\mathrm{SO}}_{4}$ is $31.4%{H}_{2}{\mathrm{SO}}_{4}$ by mass and has a density of $1.25g/\mathrm{mL}$. The molarity of the ${H}_{2}{\mathrm{SO}}_{4}$ solution is $M$ (nearest integer) [Given molar mass of ${H}_{2}{\mathrm{SO}}_{4}=98g{\mathrm{mol}}^{-1}$]

What is the EMF of the cell under the given conditions using the Nernst equation?

What is the standard EMF of the cell?

Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It should not undergo chemical change in air. (C) It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically. (D) It should be readily soluble in water. (E) \(\mathrm{KMnO}_4 ~\&~ \mathrm{NaOH}\) can be used as primary standard. Choose the correct answer from the options given below :

The emf of cell Tl \(\left|\underset{(0.001 \mathrm{M})}{\mathrm{Tl}^{+}}\right|\left|\underset{(0.01 \mathrm{M})}{\mathrm{Cu}^{2+}}\right| \mathrm{Cu}\) is \(0.83 \mathrm{~V}\) at \(298 \mathrm{~K}\). It could be increased by :

Two reactions are given below: $2{\mathrm{Fe}}_{(s)}+\frac{3}{2}{O}_{2(g)}\rightarrow {\mathrm{Fe}}_{2}{O}_{3(s)},\Delta {H}^{o}=-822\mathrm{kJ}/\mathrm{mol}$ ${C}_{(s)}+\frac{1}{2}{O}_{2(g)}\rightarrow {\mathrm{CO}}_{(g)},\Delta {H}^{o}=-110\mathrm{kJ}/\mathrm{mol}$ Then enthalpy change for following reaction $3{C}_{(s)}+{\mathrm{Fe}}_{2}{O}_{3(s)}\rightarrow 2{\mathrm{Fe}}_{(s)}+3{\mathrm{CO}}_{(g)}$

\(9.3 \mathrm{~g}\) of pure aniline is treated with bromine water at room temperature to give a white precipitate of the product ' \(\mathrm{P}\) '. The mass of product ' \(\mathrm{P}\) ' obtaind is \(26.4 \mathrm{~g}\). The percentage yield is _______ \(\%\).

For the given reaction, choose the correct expression of ${K}_{C}$ from the following: ${{\mathrm{Fe}}^{3+}}_{(\mathrm{aq})}+{{\mathrm{SCN}}^{-}}_{(\mathrm{aq})}\rightleftharpoons (\mathrm{FeSCN}{{)}^{2+}}_{(\mathrm{aq})}$

$2{\mathrm{MnO}}_{4}^{-}+{\mathrm{bI}}^{-}+{\mathrm{cH}}_{2}O\rightarrow {\mathrm{xI}}_{2}+{\mathrm{yMnO}}_{2}+{\mathrm{zOH}}^{-}$ If the above equation is balanced with integer coefficients, the value of $z$ is ________.

\(\Delta_{\text {vap }} \mathrm{H}^{\ominus}\) for water is \(+40.79 \mathrm{~kJ} \mathrm{~mol}^{-1}\) at 1 bar and \(100{ }^{\circ} \mathrm{C}\). Change in internal energy for this vapourisation under same condition is \(\qquad\) \(\mathrm{kJ} \mathrm{mol}^{-1}\). (Integer answer) (Given \(\mathrm{R}=8.3 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\))

Total number of species from the following which can undergo disproportionation reaction ___________. ${H}_{2}{O}_{2},{\mathrm{ClO}}_{3}^{-},{P}_{4},{\mathrm{Cl}}_{2},\mathrm{Ag},{\mathrm{Cu}}^{+1},{F}_{2},{\mathrm{NO}}_{2},{K}^{+}$

For the given hypothetical reactions, the equilibrium constants are as follows : \(\begin{aligned} & \mathrm{X} \rightleftharpoons \mathrm{Y} ; \mathrm{K}_1=1.0 \\ & \mathrm{Y} \rightleftharpoons \mathrm{Z} ; \mathrm{K}_2=2.0 \\ & \mathrm{Z} \rightleftharpoons \mathrm{W} ; \mathrm{K}_3=4.0 \end{aligned}\) The equilibrium constant for the reaction \(\mathrm{X} \rightleftharpoons \mathrm{W}\) is

Number of moles of methane required to produce $22g{\mathrm{CO}}_{2(g)}$ after combustion is $x\times {10}^{–2}$ moles. The value of $x$ is

For a certain reaction at $300K,K=10,$ then $\Delta G^{\circ}$ for the same reaction is – ________ $\times {10}^{-1}\mathrm{kJ}{\mathrm{mol}}^{-1}.$ (Given $R=8.314{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}$)

Which of the following electronic configuration would be associated with the highest magnetic moment ?

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ________ (Integer answer) (Given : Molar mass in \(\mathrm{g} \mathrm{mol}^{-1}\) Ethyl alcohol : 46 water: 18)

$10\mathrm{mL}$ of gaseous hydrocarbon on combustion gives $40\mathrm{mL}$ of ${\mathrm{CO}}_{2}(g)$ and $50\mathrm{mL}$ of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is _______.

For the reaction ${N}_{2}{O}_{4}(g)\rightleftharpoons 2{\mathrm{NO}}_{2}(g)$, ${K}_{p}=0.492\mathrm{atm}$ at $300K.{K}_{c}$ for the reaction at same temperature is $______\times {10}^{-2}$. (Given :$R=0.082L\mathrm{atm}{\mathrm{mol}}^{-1}{K}^{-1}$)

An artificial cell is made by encapsulating \(0.2 \mathrm{M}\) glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a \(0.05 \mathrm{M}\) solution of \(\mathrm{NaCl}\) at \(300 \mathrm{~K}\) is _______ \(\times 10^{-1}\) bar. (nearest integer). [Given : \(\mathrm{R}=0.083 \mathrm{~L} \mathrm{bar} \mathrm{mol}^{-1} \mathrm{~K}^{-1}\)] Assume complete dissociation of \(\mathrm{NaCl}\)

The electronic configuration for Neodymium is: [Atomic Number for Neodymium 60]

The values of conductivity of some materials at $298.15K$ in ${\mathrm{Sm}}^{-1}$ are $2.1\times {10}^{3},1.0\times {10}^{-16},1.2\times 10,3.91,1.5\times {10}^{-2},1\times {10}^{-7},1.0\times {10}^{3}$. The number of conductors among the materials is _____.

The correct set of four quantum numbers for the valence electron of rubidium atom $(Z=37)$ is: