Physical Chemistry PYQ — Page 54

At $300 K$ and $1$ atmospheric pressure, $10 mL$ of a hydrocarbon required $55 mL$ of ${O}_{2}$ for complete combustion, and $40 mL$ of $C{O}_{2}$ is formed. The formula of the hydrocarbon is:

For a reaction, ${N}_{2}(g)+3{H}_{2}(g)\longrightarrow 2N{H}_{3}(g)$, identify di-hydrogen $({H}_{2})$ as a limiting reagent in the following reaction mixtures.

For the following reaction, the mass of water produced from $445 g$ of ${C}_{57}{H}_{110}{O}_{6}$ is: $2 {C}_{57}{H}_{110}{O}_{6}(s)+163{O}_{2}(g)\rightarrow 114 {\mathrm{CO}}_{2}(g)+110{H}_{2}O(l)$

The decreasing order of electrical conductivity of the following aqueous solutions is: $(A)$ $0.1 M$ Formic acid, $(B)$ $0.1 M$ Acetic acid, $(C)$ $0.1 M$ Benzoic acid.

In the following reaction; $xA\rightarrow yB$ ${\mathrm{log}}_{10}⁡[-\frac{d[A]}{dt}]={\mathrm{log}}_{10}⁡[-\frac{d[B]}{dt}]+0.3010$ ‘A’ and ‘B’ respectively can be:

For the cell $\mathrm{Zn}(\mathrm{s})\left|\mathrm{Zn}^{2+}(\mathrm{aq}) \| \mathrm{M}^{\mathrm{x}+}(\mathrm{aq})\right| \mathrm{M}(\mathrm{s}),$ different half cells and their standard electrode potentials are given below:  If $\mathrm{E}_{\mathrm{Zn}^{2+} / \mathrm{Zn}}^{\circ}=-0.76 \mathrm{~V},$ which cathode will give a maximum value of $E_{\text {cell }}^{0}$ per electron transferred?

$5$ moles of $A{B}_{2}$ weigh $125\times {10}^{-3} kg$ and $10$ moles of ${A}_{2}{B}_{2}$ weigh $300\times {10}^{-3} kg$ . The molar mass of A $({M}_{A})$ in $kg {mol}^{-1}$ are:

An ideal gas undergoes isothermal compression from $5 {m}^{3}$ to $1 {m}^{3}$ against a constant external pressure of $4 N{m}^{-2}$. The heat released in this process is $24 J {\mathrm{mol}}^{-1}{K}^{-1}$ and is used to increase the pressure of $1$ mole of $\mathrm{Al}$. The temperature of $\mathrm{Al}$ increases by:

Molal depression constant for a solvent is $4.0 K kg mo{l}^{-1}.$ The depression in the freezing point of the solvent for $0.03 mol k{g}^{-1}$ solution of ${K}_{2}S{O}_{4}$ is: (Assume complete dissociation of the electrolyte)

Which of the following combination of statements is true regarding the interpretation of the atomic orbitals? $(A)$ An electron in an orbital of high angular momentum stays away from the nucleus than an electron in the orbital of lower angular momentum. $(B)$ For a given value of the principal quantum number, the size of the orbit is inversely proportional to the azimuthal quantum number. $(C)$ According to wave mechanics, the ground state angular momentum is equal to $\frac{h}{2\pi }$ . $(D)$ The plot of $\psi$ Vs $r$ for various azimuthal quantum numbers, shows peak shifting towards higher $r$ value.

$5$ moles of an ideal gas at $100 K$ are allowed to undergo reversible compression till its temperature becomes $200 K.$ If ${C}_{V}=28 J {K}^{-1},$ calculate $\Delta U$ and $\Delta pV$ for the process. $(R=8.0 J {K}^{-1} mo{l}^{-1})$

In the reaction of oxalate with permanganate in acidic medium, the number of electrons involved in producing one molecule of ${\mathrm{CO}}_{2}$ is:

Consider the given plots for a reaction obeying Arrhenius equation $(0^{\circ}C<T<300^{\circ}C):$ ($K$and ${E}_{a}$ are rate constant and activetion energy, respectively ) (I)  (II) 

$1 g$ of a non-volatile non-electrolyte solute is dissolved in $100 g$ of two different solvents $A$ and B whose ebullioscopic constants are in the ratio of $1:5$. The ratio of the elevation in their boiling points, $\frac{\Delta {T}_{b}(A)}{\Delta {T}_{b}(B)}$, is: (assuming they have the same molar mass)

If the standard electrode potential for a cell is $2 V$ at $300 K,$ the equilibrium constant $(K)$ for the reaction. $Zn(s)+C{u}^{2+}(aq)\rightleftharpoons Z{n}^{2+}(aq)+Cu(s)$ at $300 K$ is approximately: $(R=8 J{K}^{-1}mo{l}^{-1}, F=96000 C mo{l}^{-1})$

Heat treatment of muscular pain involves radiation of wavelength of about $900 \mathrm{nm}$. Which spectral line of $\mathrm{H}$ atom is suitable for this purpose? $\left[\mathrm{R}_{\mathrm{H}}=1 \times 10^{5} \mathrm{~cm}^{-1} \cdot \mathrm{h}=6.6 \times 10^{-34} \mathrm{Js}, \mathrm{c}=3 \times 10^{8} \mathrm{~ms}^{-1}\right]$

The combination of plots which does not represent isothermal expansion of an ideal gas is $(A)$  $(B)$  $(C)$  $(D)$ 

The amount of sugar $({C}_{12}{H}_{22}{O}_{11})$ required to prepare $2L$ of its $0.1 M$ aqueous solution is:

Consider the following reduction processes: ${\mathrm{Zn}}^{2+}+2{e}^{-}\rightarrow \mathrm{Zn}(s);{E}^{o}=-0.76 V$ ${\mathrm{Ca}}^{2+}+2{e}^{-}\rightarrow \mathrm{Ca}(s);{E}^{o}=-2.87 V$ ${\mathrm{Mg}}^{2+}+2{e}^{-}\rightarrow \mathrm{Mg}(s);{E}^{o}=-2.36 V$ ${\mathrm{Ni}}^{2+}+2{e}^{-}\rightarrow \mathrm{Ni}(s);{E}^{o}=-0.25 V$ The reducing power of the metals increases in the order:

The percentage composition of carbon by mole in methane is:

The ground state energy of a hydrogen atom is $-13.6 \mathrm{eV}$. The energy of second excited state of ${\mathrm{He}}^{+}$ ion in $\mathrm{eV}$ is:

Consider the following reversible chemical reactions: ${A}_{2}(g)+{B}_{2}(g)\overset{{k}_{1}}{\rightleftharpoons }2AB(g)$ .....(1) $6AB(g)\overset{{k}_{2}}{\rightleftharpoons }3{A}_{2}(g)+3{B}_{2}(g)$ .....(2) The relation between ${K}_{1}$ and ${K}_{2}$ is:

For the following reaction, equilibrium constant are given: $S(s)+{O}_{2}(g)\rightleftharpoons S{O}_{2}(g);{K}_{1}={10}^{52}$ $2S(s)+3{O}_{2}(g)\rightleftharpoons 2S{O}_{3}(g);{K}_{2}={10}^{129}$ The equilibrium constant for the reaction, $2{SO}_{2}(g)+{O}_{2}(g)\rightleftharpoons 2S{O}_{3}(g)$ is:

Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non- expansion work is zero)