Physical Chemistry PYQ — Page 38

For the given reactions ${\mathrm{Sn}}^{2+}+2{e}^{-}\rightarrow \mathrm{Sn}$ ${\mathrm{Sn}}^{4+}+4{e}^{-}\rightarrow \mathrm{Sn}$ the electrode potentials are ; ${E}_{{\mathrm{Sn}}^{2+}/\mathrm{Sn}}^{^{\circ}}=-0.140V$ and ${E}_{{\mathrm{Sn}}^{4+}/\mathrm{Sn}}^{^{\circ}}=0.010V$. The magnitude of standard electrode potential for ${\mathrm{Sn}}^{4+}/{\mathrm{Sn}}^{2+}$ i.e. ${E}_{{\mathrm{Sn}}^{4+}/{\mathrm{Sn}}^{2+}}^{^{\circ}}$ is____$\times {10}^{-2}V$(Nearest integer)

Which of the following sets of quantum numbers is not allowed?

${K}_{a}$ for butyric acid $({C}_{3}{H}_{7}\mathrm{COOH})$ is $2\times {10}^{-5}$. The$\mathrm{pH}$ of $0.2M$ solution of butyric acid is____$\times {10}^{-1}$. (Nearest integer) [Given $\mathrm{log}2=0.30$]

For a reaction $A\rightarrow 2B+C$ the half lives are $100s$ and $50s$ when the concentration of reactant $A$ is $0.5$ and $1.0\mathrm{mol}L=$ respectively. The order of the reaction is

A $1.84\mathrm{mg}$ sample of polyhydric alcoholic compound '$X$' of molar mass $92.0g/\mathrm{mol}$ gave $1.344\mathrm{mL}$ of ${H}_{2}$ gas at STP. The number of alcoholic hydrogen present in compound '$X$' is

${\mathrm{Ka}}_{1},{\mathrm{Ka}}_{2}$ and ${\mathrm{Ka}}_{3}$ are the respective ionization constants for the following reactions $(a),(b)$ and $(c)$. (a) ${H}_{2}{C}_{2}{O}_{4}\rightleftharpoons {H}^{+}+{\mathrm{HC}}_{2}{O}_{4}^{-}$ (b) ${\mathrm{HC}}_{2}{O}_{4}^{-}\rightleftharpoons {H}^{+}+{\mathrm{HC}}_{2}{O}_{4}^{2-}$ (c) ${H}_{2}{C}_{2}{O}_{4}\rightleftharpoons 2{H}^{+}+{C}_{2}{O}_{4}^{2-}$ The relationship between ${K}_{{a}_{1}},{K}_{{a}_{2}}$ and ${K}_{{a}_{3}}$ is given as

A gas ( Molar mass $=280g{\mathrm{mol}}^{-1}$) was burnt in excess ${O}_{2}$ in a constant volume calorimeter and during combustion the temperature of calorimeter increased from $298.0K$ to $298.45K$. If the heat capacity of calorimeter is $2.5\mathrm{kJ}{K}^{-1}$ and enthalpy of combustion of gas is $9\mathrm{kJ}{\mathrm{mol}}^{-1}$ then amount of gas burnt is____$g$.

A solution containing $2.5\times {10}^{-3}\mathrm{kg}$ of a solute dissolved in $75\times {10}^{-3}\mathrm{kg}$ of water boils at $373.535K$. The molar mass of the solute is ${\mathrm{mol}}^{-1}\cdot$ [nearest integer] (Given : ${K}_{b}({H}_{2}O)=0.52K\mathrm{kg}{\mathrm{mol}}^{-1}$ and boiling point of water $=373.15K$)

$1L$ aqueous solution of ${H}_{2}{\mathrm{SO}}_{4}$ contains $0.02m\mathrm{mol}{H}_{2}{\mathrm{SO}}_{4}.50%$ of this solution is diluted with deionized water to give $1L$ solution $(A)$. In solution $(A)$, $0.01m\mathrm{mol}$ of ${H}_{2}{\mathrm{SO}}_{4}$ are added. Total $m$ mols of ${H}_{2}{\mathrm{SO}}_{4}$ in the final solution is____$\times {10}^{-3}m\mathrm{moles}$.

When a certain amount of solid $A$ is dissolved in $100g$ of water at $25^{\circ}C$ to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is $23.76\mathrm{mmHg}$. The number of moles of solute $A$ added is

Catalyst A reduces the activation energy for a reaction by $10\mathrm{kJ}{\mathrm{mol}}^{-1}$ at $300K$. The ratio of rate constants, $\frac{{k}_{T},\mathrm{Catalysed}}{{k}_{T},\mathrm{Uncatalysed}}$ is ${e}^{x}$. The value of $x$ is____[nearest integer] [Assume that the pre-exponential factor is same in both the cases. Given $R=8.31J{K}^{-1}{\mathrm{mol}}^{-1}$]

Manganese $(\mathrm{VI})$ has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is

The cell potential for the given cell at $298K\mathrm{Pt}|{H}_{2}(g,1\mathrm{bar})||{H}^{+}(\mathrm{aq})\|{\mathrm{Cu}}^{2+}(\mathrm{aq})|\mathrm{Cu}(s)$ is $0.31V$. The $\mathrm{pH}$ of the acidic solution is found to be $3$, whereas the concentration of ${\mathrm{Cu}}^{2+}$ is ${10}^{x}M$. The value of $x$ is _________. (Given: ${E}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^{\Theta }=0.34V$ and $\frac{2.303\mathrm{RT}}{F}=0.06V$)

The normality of ${H}_{2}{\mathrm{SO}}_{4}$ in the solution obtained on mixing $100\mathrm{mL}$ of $0.1M{H}_{2}{\mathrm{SO}}_{4}$ with $50\mathrm{mL}$ of $0.1M\mathrm{NaOH}$ is____$\times {10}^{-1}N$.

The elevation in boiling point for $1$ molal solution of non-volatile solute $A$ is $3K$. The depression in freezing point for $2$ molal solution of $A$ in the same solvent is $6K$. The ratio of ${K}_{b}$ and ${K}_{f}$ i.e., ${K}_{b}/{K}_{f}$ is $1:X$. The value of $X$ is

For a cell, $\mathrm{Cu}(s){\mathrm{Cu}}^{2+}(0.001M)|{\mathrm{Ag}}^{+}(0.01M)|\mathrm{Ag}(s)$the cell potential is found to be $0.43V$ at $298K$. The magnitude of standard electrode potential for ${\mathrm{Cu}}^{2+}|\mathrm{Cu}$ is____$\times {10}^{-2}V$ $[\mathrm{Given}:{E}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\Theta }=0.80V\mathrm{and}\frac{2.303\mathrm{RT}}{F}=0.06V]$

The depression in freezing point observed for a formic acid solution of concentration $0.5\mathrm{mL}{L}^{-1}$ is $0.0405^{\circ}C$. Density of formic acid is $1.05g{\mathrm{mL}}^{-1}$. The Van't Hoff factor of the formic acid solution is nearly: (Given for water ${k}_{f}=1.86K\mathrm{kg}{\mathrm{mol}}^{-1}$)

$2\mathrm{NO}+2{H}_{2}\rightarrow {N}_{2}+2{H}_{2}O$ The above reaction has been studied at $800^{\circ}C$. The related data are given in the table below <table class="pyq-table"><tbody><tr><td>Reaction serial number</td><td>Initial pressure of${H}_{2}/\mathrm{kPa}$</td><td>Initial Pressure of $\mathrm{NO}/\mathrm{kPa}$</td><td>Initial rate $(\frac{-\mathrm{dp}}{\mathrm{dt}})/(\mathrm{kPa}/s)$</td></tr><tr><td>$1$</td><td>$65.6$</td><td>$40.0$</td><td>$0.135$</td></tr><tr><td>$2$</td><td>$65.6$</td><td>$20.1$</td><td>$0.033$</td></tr><tr><td>$3$</td><td>$38.6$</td><td>$65.6$</td><td>$0.214$</td></tr><tr><td>$4$</td><td>$19.2$</td><td>$65.6$</td><td>$0.106$</td></tr></tbody></table>The order of the reaction with respect to NO is____

The standard entropy change for the reaction $4\mathrm{Fe}(s)+3{O}_{2}(g)\rightarrow 2{\mathrm{Fe}}_{2}{O}_{3}(s)$ is $-550J{K}^{-1}$ at $298K$ [Given : The standard enthalpy change for the reaction is $-165\mathrm{kJ}{\mathrm{mol}}^{-1}$]. The temperature in $K$ at which the reaction attains equilibrium is (Nearest Integer)

In the industrial production of which of the following, molecular hydrogen is obtained as a bye product.

$\mathrm{Cu}(s)+{\mathrm{Sn}}^{2+}(0.001M)\rightarrow {\mathrm{Cu}}^{2+}(0.01M)+\mathrm{Sn}(s)$ The Gibbs free energy change for the above reaction at $298K$ is $x\times {10}^{-1}\mathrm{kJ}{\mathrm{mol}}^{-1}$. The value of $x$ is____[nearest integer] [Given : ${E}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^{\ominus }=0.34V;{E}_{{\mathrm{Sn}}^{2+}/\mathrm{Sn}}^{\ominus }=-0.14V;F=96500{\mathrm{Cmol}}^{-1}$]

The number of radial and angular nodes in $4d$ orbital are, respectively

The correct order of reduction potentials of the following pairs is A. ${\mathrm{Cl}}_{2}/{\mathrm{Cl}}^{-}$ B. ${I}_{2}/{I}^{-}$ C. ${\mathrm{Ag}}^{+}/\mathrm{Ag}$ D. ${\mathrm{Na}}^{+}/\mathrm{Na}$ E. ${\mathrm{Li}}^{+}/\mathrm{Li}$ Choose the correct answer from the options given below.

The amount of charge in $F$ (Faraday) required to obtain one mole of iron from ${\mathrm{Fe}}_{3}{O}_{4}$ is ______. (Round off the answer to the nearest integer)