Physical Chemistry PYQ — Page 41

A $1$ molal ${K}_{4}\mathrm{Fe}(\mathrm{CN}{)}_{6}$ solution has a degree of dissociation of $0.4.$ Its boiling point is equal to that of another solution which contains $18.1$ weight percent of a non electrolytic solute $A$. The molar mass of $A$ is _____ u. (Round off to the Nearest Integer). [Density of water $=1.0g{\mathrm{cm}}^{-3}]$

The solubility of $\mathrm{AgCN}$ in a buffer solution of $\mathrm{pH}=3$ is $x$. The value of $x$ is: [Assume : No cyano complex is formed ; ${K}_{\mathrm{sp}}(\mathrm{AgCN})=2.2\times {10}^{-16}$ and ${K}_{a}(\mathrm{HCN})=6.2\times {10}^{-10}$]

Value of ${K}_{P}$ for the equilibrium reaction ${N}_{2}{O}_{4}(g)\rightleftharpoons 2{\mathrm{NO}}_{2(g)}$ at $288K$ is $47.9.$ The ${K}_{C}$ for this reaction at same temperature is (Nearest integer) $(R=0.083L\mathrm{bar}{K}^{-1}{\mathrm{mol}}^{-1})$

$2{\mathrm{MnO}}_{4}^{-}+{\mathrm{bC}}_{2}{O}_{4}^{2-}+{\mathrm{cH}}^{+}\rightarrow {\mathrm{xMn}}^{2+}+{\mathrm{yCO}}_{2}+{\mathrm{zH}}_{2}O$ If the above equation is balanced with integer coefficients, the value of $c$ is _______ . (Round off to the Nearest Integer).

$A$ and $B$ decompose via first order kinetics with half-lives $54.0\mathrm{min}$ and $18.0\mathrm{min}$ respectively. Starting from an equimolar non-reactive mixture of $A$ and $B$, the time taken for the concentration of $A$ to become $16$ times that of $B$ is ______ $\mathrm{min}$. (Round off to the Nearest Integer).

For the reaction $2{\mathrm{Fe}}^{3+}(\mathrm{aq})+2{I}^{-}(\mathrm{aq})\rightarrow 2{\mathrm{Fe}}^{2+}(\mathrm{aq})+{I}_{2}(s)$ the magnitude of the standard molar free energy change, ${\Delta }_{r}{G}_{m}^{\circ }=-$______$\mathrm{kJ}$ (Round off to the Nearest Integer). 

Consider the complete combustion of butane, the amount of butane utilized to produce $72.0g$ of water is ______ $\times {10}^{-1}g$. (in nearest integer)

Consider titration of $\mathrm{NaOH}$ solution versus $1.25M$ oxalic acid solution. At the end point following burette readings were obtained. (i) $4.5\mathrm{mL}$ (ii) $4.5\mathrm{mL}$ (iii) $4.4\mathrm{mL}$ (iv) $4.4\mathrm{mL}$ (v) $4.4\mathrm{mL}$ If the volume of oxalic acid taken was $10.0\mathrm{mL}$ then the molarity of the $\mathrm{NaOH}$ solution is ___$M$. (Rounded-off to the nearest integer)

The orbital having two radial as well as two angular nodes is:

Complete combustion of $3g$ of ethane gives $x\times {10}^{22}\text{molecules}$ of water. The value of $x$ is ______ (Round off to the Nearest Integer). $[\text{Use}:{N}_{A}=6.023\times {10}^{23};\text{Atomic masses in}u:C:12.0;O:16.0;H:1.0]$

The wavelength of electrons accelerated from rest through a potential difference of $40\mathrm{kV}$ is $X\times {10}^{-12}m.$ The value of $x$ is. (Nearest integer) Given: Mass of electron $=9.1\times {10}^{-31}\mathrm{kg}$ Charge on an electron $=1.6\times {10}^{-19}C$ Planck's constant $=6.63\times {10}^{-34}\mathrm{Js}$

The number of atoms in $8g$ of sodium is $x\times {10}^{23}.$ The value of $x$ is _____ . (Nearest integer) $[\text{ Given : }{N}_{A}=6.02\times {10}^{23}{\mathrm{mol}}^{-1}\text{ Atomic mass of }\mathrm{Na}=23.0u]$

$4.5g$ of compound $A(M.W.=90)$ was used to make $250\mathrm{mL}$ of its aqueous solution. The molarity of the solution in $M$ is $x\times {10}^{-1}.$ The value of $x$ is_____ (Rounded off to the nearest integer)

If the standard molar enthalpy change for combustion of graphite powder is $-2.48\times {10}^{2}\mathrm{kJ}{\mathrm{mol}}^{-1}$, the amount of heat generated on combustion of $1g$ of graphite powder in $\mathrm{kJ}$ (Nearest integer):

Which of the following is an intensive property?

The elevation in boiling point of a solution depends on:

The molar solubility of $\mathrm{Zn}(\mathrm{OH}{)}_{2}$ in $0.1\mathrm{MNaOH}$ solution is $x\times {10}^{-18}M.$ The value of $x$ is _____ . (Nearest integer) $(\text{Given : The solubility product of }\mathrm{Zn}(\mathrm{OH}{)}_{2}\text{is}2\times {10}^{-20})$

Consider the following cell reaction ${\mathrm{Cd}}_{(s)}+{\mathrm{Hg}}_{2}{\mathrm{SO}}_{4(s)}+\frac{9}{5}{H}_{2}{O}_{(l)}\rightleftharpoons {\mathrm{CdSO}}_{4}\cdot \frac{9}{5}{H}_{2}{O}_{(s)}+2{\mathrm{Hg}}_{(l)}.$ The value of ${E}_{\mathrm{cell}}^{0}$ is $4.315V$ at $25^{\circ}C.$ If $\Delta H^{\circ}=-825.2\mathrm{kJ}{\mathrm{mol}}^{-1},$ the standard entropy change $\Delta S^{\circ}$ in $J{K}^{-1}$ is _________ . (Nearest integer) [Given : Faraday constant $=96487C{\mathrm{mol}}^{-1}$]

The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, $10%$ of the virus is inactivated. The rate constant for viral inactivation is $___\times {10}^{-3}{\mathrm{min}}^{-1}.$ (Nearest integer) [Use : $\mathrm{ln}10=2.303;{\mathrm{log}}_{10}3=0.477$ property of logarithm$:\mathrm{log}{x}^{y}=y\mathrm{log}x]$

$0.01$ moles of a weak acid $\mathrm{HA}({K}_{a}=2.0\times {10}^{-6})$ is dissolved in $1.0L$ of $0.1M\mathrm{HCl}$ solution. The degree of dissociation of $\mathrm{HA}$ is __________ $\times {10}^{-5}$ (Round off to the Nearest Integer). [Neglect volume change on adding $\mathrm{HA}$ and assume degree of dissociation $<<1$]

The $\mathrm{pH}$ of a solution obtained by mixing $50\mathrm{mL}$ of $1M\mathrm{HCl}$ and $30\mathrm{mL}$ of $1M\mathrm{NaOH}$ is $x\times {10}^{-4}.$ The value of $x$ is (Nearest integer) $[\mathrm{log}2.5=0.3979]$

The equilibrium constant for the reaction $A(s)\rightleftharpoons M(s)+\frac{1}{2}{O}_{2}(g)$ is ${K}_{p}=4.$ At equilibrium, the partial pressure of ${O}_{2}$ is _____ atm. (Round off to the nearest integer)

$100\mathrm{mL}$ of ${\mathrm{Na}}_{3}{\mathrm{PO}}_{4}$ solution contains $3.45g$ of sodium. The molarity of the solution is .....$\times {10}^{-2}\mathrm{mol}{L}^{-1}$. (Nearest integer) [Atomic Masses - $\mathrm{Na}:23.0u,O:16.0u,P:31.0u]$

 Consider the above reaction where $6.1g$ of benzoic acid is used to get $7.8g$ of m-bromo benzoic acid. The percentage yield of the product is ___ . (Round off to the Nearest integer) [Given : Atomic masses : $C=12.0u,H:1.0u,O:16.0u,\mathrm{Br}=80.0u$]