Physical Chemistry PYQ — Page 26

The number of given statement/s which is/are correct is_____ (A) The stronger the temperature dependence of the rate constant, the higher is the activation energy. (B) If a reaction has zero activation energy, its rate is independent of temperature. (C) The stronger the temperature dependence of the rate constant, the smaller is the activation energy. (D) If there is no correlation between the temperature and the rate constant then it means that the reaction has negative activation energy.

Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n=4$ to $n=2$ of ${\mathrm{He}}^{+}$spectrum

At $298K$, the solubility of silver chloride in water is $1.434\times {10}^{-3}g{L}^{-1}$. The value of $-{\mathrm{logK}}_{\mathrm{sp}}$ for silver chloride is (Given mass of Ag is $107.9g{\mathrm{mol}}^{-1}$, and mass of $\mathrm{Cl}$ is $35.5g{\mathrm{mol}}^{-1}$ )

The pH of a 0.1 M HCl solution is:

For an isothermal reversible expansion of an ideal gas, which of the following is true?

At what $\mathrm{pH}$, given half cell ${\mathrm{MnO}}_{4}^{-}(0.1M)\mid {\mathrm{Mn}}^{2+}$ $(0.001M)$ will have electrode potential of $1.282V$ ? (Nearest Integer) Given ${E}_{{\mathrm{MnO}}_{4}^{-}/{\mathrm{Mn}}^{2+}}^{o}=1.54V,\frac{2.303\mathrm{RT}}{F}=0.059V$

At $298K$, the standard reduction potential for ${\mathrm{Cu}}^{2+}/\mathrm{Cu}$ electrode is $0.34V$. Given : ${K}_{\mathrm{sp}}\mathrm{Cu}(\mathrm{OH}{)}_{2}=1\times {10}^{-20}$ Take $\frac{2.303\mathrm{RT}}{F}=0.059V$ The reduction potential at $\mathrm{pH}=14$ for the above couple is $(-)x\times {10}^{-2}V$. The value of x is

The number of correct statement/s involving equilibria in physical processes from the following is ________ (A) Equilibrium is possible only in a closed system at a given temperature. (B) Both the opposing processes occur at the same rate. (C) When equilibrium is attained at a given temperature, the value of all its parameters became equal (D) For dissolution of solids in liquids, the solubility is constant at a given temperature.

When ${\mathrm{Fe}}_{0.93}O$ is heated in presence of oxygen, it converts to ${\mathrm{Fe}}_{2}{O}_{3}$. The number of correct statement/s from the following is ______ . A. The equivalent weight of ${\mathrm{Fe}}_{0.93}O$ is $\frac{\mathrm{Molecular}\mathrm{weight}}{0.79}$ B. The number of moles of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in $1$ mole of ${\mathrm{Fe}}_{0.93}O$ is $0.79$ and $0.14$ respectively. C. ${\mathrm{Fe}}_{0.93}O$ is metal deficient with lattice comprising of cubic closed packed arrangement of ${O}^{2-}$ ions. D. The $%$ composition of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$ in ${\mathrm{Fe}}_{0.93}O$ is $85%$ and $15%$ respectively.

$0.5g$ of an organic compound (X) with $60%$ carbon will produce $\times {10}^{-1}g$ of ${\mathrm{CO}}_{2}$ on complete combustion.

The graph which represents the following reaction is: ${({C}_{6}{H}_{5})}_{3}C-\mathrm{Cl}\frac{{\mathrm{OH}}^{-}}{\mathrm{Pyridine}}{({C}_{6}{H}_{5})}_{3}C-\mathrm{OH}$

For independent process at $300K$. <table class="pyq-table"><tbody><tr><td>Process</td><td>$\Delta H/{\mathrm{kJmol}}^{-1}$</td><td>$\Delta S/{\mathrm{JK}}^{-1}$</td></tr><tr><td>$A$</td><td>$-25$</td><td>$-80$</td></tr><tr><td>$B$</td><td>$-22$</td><td>$40$</td></tr><tr><td>$C$</td><td>$25$</td><td>$-50$</td></tr><tr><td>$D$</td><td>$22$</td><td>$20$</td></tr></tbody></table>The number of non-spontaneous process from the following is _____ .

$20\mathrm{mL}$ of $0.1\mathrm{MNaOH}$ is added to $50\mathrm{mL}$ of $0.1M$ acetic acid solution. The $\mathrm{pH}$ of the resulting solution is $\times {10}^{-2}$. (Nearest integer) Given : $\mathrm{pK}a({\mathrm{CH}}_{3}\mathrm{COOH})=4.76$ $\mathrm{log}2=0.30$ $\mathrm{log}3=0.48$

Consider the cell $\mathrm{Pt}(s)|{H}_{2}(s)(\mathrm{latm})|{H}^{+}(\mathrm{aq},[{H}^{+}]=1)||{\mathrm{Fe}}^{3+}(\mathrm{aq}),{\mathrm{Fe}}^{2+}(\mathrm{aq})\mid Pt(s)$ Given: ${E}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{\circ}=0.771V$ and ${E}_{{H}^{+}/\frac{1}{2}{H}_{2}}^{\circ}=0V,T=298K$ If the potential of the cell is $0.712V$ the ratio of concentration of ${\mathrm{Fe}}^{2+}$ to ${\mathrm{Fe}}^{3+}$ is (Nearest integer)

Given below are two statements: Statement I: In redox titration, the indicators used are sensitive to change in $\mathrm{pH}$ of the solution. Statement II: In acid-base titration, the indicators used are sensitive to change in oxidation potential. In the light of the above statements, choose the most appropriate answer from the options given below

The electrode potential of the following half cell at $298K$ $X|{X}^{2+}(0.001M)\|{Y}^{2+}(0.01M)|Y$ is _____ $\times {10}^{-2}V$ (Nearest integer) Given : ${E}_{{X}^{2+}\mid X}^{0}=-2.36V$ ${E}_{{Y}^{2+}Y}^{0}=+0.36V$ $\frac{2.303\mathrm{RT}}{F}=0.06V$

Given below are two statements Statement I : According to Bohr’s model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised. Statement II : The concept of electron in Bohr’s orbit, violates the Heisenberg uncertainty principle. In the light of the above statements, choose the most appropriate answer from the options given below

$30.4\mathrm{kJ}$ of heat is required to melt one mole of sodium chloride and the entropy change at the melting point is $28.4J{K}^{–1}{\mathrm{mol}}^{–1}$ at $1\mathrm{atm}$. The melting point of sodium chloride is _______ $K$ (Nearest Integer)

$A(g)\rightleftharpoons 2B(g)+C(g)$ For the given reaction, if the initial pressure is $450\mathrm{mmHg}$ and the pressure at time $t$ is$720\mathrm{mmHg}$ at a constant temperature$T$ and constant volume $V$. The fraction of $A(g)$ decomposed under these conditions is $x\times {10}^{-1}$. The value of $x$ is (nearest integer)

Match List I with List II. <table class="pyq-table"><tbody><tr><td colspan="2" rowspan="1">List I</td><td colspan="2" rowspan="1">List II</td></tr><tr><td>A.</td><td>van't Hoff factor, i</td><td>I.</td><td>Cryoscopic constant</td></tr><tr><td>B.</td><td>${k}_{f}$</td><td>II.</td><td>Isotonic solutions</td></tr><tr><td>C.</td><td>Solutions with same osmotic pressure</td><td>III.</td><td>$\frac{\text{Normal molar mass}}{\text{Abnormal molar mas}}$</td></tr><tr><td>D.</td><td>Azeotropes</td><td>IV.</td><td>Solutions with same composition of vapour above it</td></tr></tbody></table>Choose the correct answer from the options given below:

A solution of sugar is obtained by mixing $200g$ of its $25%$ solution and $500g$of its $40%$solution (both by mass). The mass percentage of the resulting sugar solution is _______ (Nearest integer)

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: $3.1500g$of hydrated oxalic acid dissolved in water to make $250.0mL$ solution will result in $0.1M$ oxalic acid solution. Reason R: Molar mass of hydrated oxalic acid is $126gmo{l}^{–1}$ . In the light of the above statements, choose the correct answer from the options given below:

The number of following statement/s which is/are incorrect is ______ A) Line emission spectra are used to study the electronic structure B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet. C) An absorption spectrum is like the photographic negative of an emission spectrum D) The element helium was discovered in the sun by spectroscopic method

Consider the following data Heat of combustion of ${H}_{2}(g)=–241.8\mathrm{kJ}{\mathrm{mol}}^{–1}$ Heat of combustion of $C(s)=–393.5\mathrm{kJ}{\mathrm{mol}}^{–1}$ Heat of combustion of ${C}_{2}{H}_{5}\mathrm{OH}(l)$$=–1234.7\mathrm{kJ}{\mathrm{mol}}^{–1}$ The heat of formation of ${C}_{2}{H}_{5}\mathrm{OH}(l)$ is $(–)$ _____ $\mathrm{kJ}{\mathrm{mol}}^{–1}$ (Nearest integer).