Physical Chemistry PYQ — Page 25

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 ${E}_{{\mathrm{MnO}}_{4}^{-}/{\mathrm{Mn}}^{2+}}^{o}=1.54V,\frac{2.303\mathrm{RT}}{F}=0.059V$

$0.5g$ 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: ${({C}_{6}{H}_{5})}_{3}C-\mathrm{Cl}\frac{{\mathrm{OH}}^{-}}{\mathrm{Pyridine}}{({C}_{6}{H}_{5})}_{3}C-\mathrm{OH}$

${\mathrm{KMnO}}_{4}$ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute ${H}_{2}{\mathrm{SO}}_{4}.$ Number of water molecules produced for $2$ molecules of ${\mathrm{KMnO}}_{4}$ is $_______$

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)

Number of hydrogen atoms per molecule of a hydrocarbon A having $85.8%$ carbon is (Given : Molar mass of $A=84g{\mathrm{mol}}^{-1}$ )

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 radius of the 2$^{nd}$ orbit of ${\mathrm{Li}}^{2+}$ is $x$. The expected radius of the 3$^{rd}$ orbit of ${\mathrm{Be}}^{3+}$ is

$0.004M{K}_{2}{\mathrm{SO}}_{4}$ solution is isotonic with $0.01M$ glucose solution. Percentage dissociation of ${K}_{2}{\mathrm{SO}}_{4}$ is _____ (Nearest integer)

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 : ${E}_{{X}^{2+}\mid X}^{0}=-2.36V$ ${E}_{{Y}^{2+}Y}^{0}=+0.36V$ $\frac{2.303\mathrm{RT}}{F}=0.06V$

If the $\mathrm{pKa}$ of lactic acid is $5$, then the $\mathrm{pH}$ of $0.005M$ calcium lactate solution at $25^{\circ}C$ is __________ $\times {10}^{–1}$ (Nearest integer)

Solid fuel used in rocket is a mixture of ${\mathrm{Fe}}_{2}{O}_{3}$and $\mathrm{Al}$ (in ratio $1:2$). The heat evolved $(\mathrm{kJ})$ per gram of the mixture is _____ (Nearest integer) Given ${\Delta H}_{f}^{0}({\mathrm{Al}}_{2}{O}_{3})=-1700\mathrm{kJ}{\mathrm{mol}}^{-1}$ ${\Delta H}_{f}^{0}({\mathrm{Fe}}_{2}{O}_{3})=-840\mathrm{kJ}{\mathrm{mol}}^{-1}$ Molar mass of $\mathrm{Fe},\mathrm{AI}$ and $O$ are $56,27$ and $16g{\mathrm{mol}}^{–1}$ respectively

The number of atomic orbitals from the following having $5$ radial nodes is $7s,7p,6s,8p,8d$

$A(g)\rightleftharpoons 2B(g)+C(g)$ 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:

The energy of an electron in the first Bohr orbit of hydrogen atom is $-2.18\times {10}^{-18}J$ Its energy in the third Bohr orbit is$_______.$

A metal chloride contains $55.0%$ of chlorine by weight. $100\mathrm{mL}$ vapours of the metal chloride at STP weigh $0.57g$. The molecular formula of the metal chloride is (Given: Atomic mass of chlorine is $35.5u$)

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 molecules and moles in $2.8375$ litres of ${O}_{2}$ at $\mathrm{STP}$ are respectively

The density of $3M$ solution of $\mathrm{NaCl}$ is $1.0g{\mathrm{mL}}^{-1}$. Molality of the solution is $______\times {10}^{-2}m$ (Nearest integer). Given: Molar mass of $\mathrm{Na}$ and $\mathrm{Cl}$ is $23$ and $35.5g$ ${\mathrm{mol}}^{-1}$ respectively.