Physical Chemistry PYQ — Page 36

If ${O}_{2}$ gas is bubbled through water at $303K$, the number of millimoles of ${O}_{2}$ gas that dissolve in $1$ litre of water is____(Nearest integer) (Given : Henry's Law constant for ${O}_{2}$ at $303K$ is $46.82k$ bar and partial pressure of ${O}_{2}=0.920$ bar) (Assume solubility of ${O}_{2}$ in water is too small, nearly negligible)

A solution of ${\mathrm{Fe}}_{2}{({\mathrm{SO}}_{4})}_{3}$ is electrolyzed for '$x$' min with a current of $1.5A$ to deposit $0.3482g$ of $\mathrm{Fe}$. The value of $x$ is - [nearest integer] Given : $1F=96500{\mathrm{Cmol}}^{-1}$. Atomic mass of $\mathrm{Fe}=56{\mathrm{gmol}}^{-1}$

At $25^{\circ}C$ and $1$ atm pressure, the enthalpies of combustion are as given below: <table class="pyq-table"><tbody><tr><td>Substance</td><td>${H}_{2}$</td><td>$C$ (graphite)</td><td>${C}_{2}{H}_{6}(g)$</td></tr><tr><td>$\frac{{\Delta }_{c}{H}^{\Theta }}{{\mathrm{kJmol}}^{-1}}$</td><td>$-286.0$</td><td>$-394.0$</td><td>$-1560.0$</td></tr></tbody></table>The enthalpy of formation of ethane is

It has been found that for a chemical reaction with rise in temperature by $9K$ the rate constant gets doubled. Assuming a reaction to be occurring at $300K$, the value of activation energy is found to be ${\mathrm{kJmol}}^{-1}$. [nearest integer] (Given $\mathrm{ln}10=2.3,R=8.3J{K}^{-1}{\mathrm{mol}}^{-1},\mathrm{log}2=0.30$)

Given below are two statements : one is labelled as Assertion and the other is labelled as Reason. Assertion: At $10^{\circ}C$, the density of a $5M$ solution of $\mathrm{KCl}$ [atomic masses of $K&\mathrm{Cl}$ are $39&35.5g{\mathrm{mol}}^{-1}$ respectively], is '$x$' ${\mathrm{gml}}^{-1}$. The solution is cooled to $-21^{\circ}C$. The molality of the solution will remain unchanged. Reason: The molality of a solution does not change with temperature as mass remains unaffected with temperature. In the light of the above statements, choose the correct answer from the options given below.

A commercially sold conc. $\mathrm{HCl}$ is $35%\mathrm{HCl}$ by mass. If the density of this commercial acid is $1.46g/\mathrm{mL}$, the molarity of this solution is : (Atomic mass : $\mathrm{Cl}=35.5\mathrm{amu},H=1\mathrm{amu}$)

Given below are two statements: Statement I: For $\mathrm{KI}$, molar conductivity increases steeply with dilution. Statement II: For carbonic acid, molar conductivity increases slowly with dilution. In the light of the above statements, choose the correct answer from the options given below

The enthalpy of combustion of propane, graphite and dihydrogen at $298K$ are: $-2220.0\mathrm{kJ}{\mathrm{mol}}^{-1}$, $-393.5\mathrm{kJ}{\mathrm{mol}}^{-1}$ and $-285.8\mathrm{kJ}{\mathrm{mol}}^{-1}$ respectively. The magnitude enthalpy of formation of propane $({C}_{3}{H}_{8})$ is _____ ${\mathrm{kJmol}}^{-1}$. (Nearest integer)

${\mathrm{PCl}}_{5}$ dissociates as ${\mathrm{PCl}}_{5}(g)\rightleftharpoons {\mathrm{PCl}}_{3}(g)+{\mathrm{Cl}}_{2}(g)$ $5$ moles of ${\mathrm{PCl}}_{5}$ are placed in a $200$ litre vessel which contains $2$ moles of ${N}_{2}$ and is maintained at $600K$. The equilibrium pressure is $2.46\mathrm{atm}$. The equilibrium constant ${K}_{p}$ for the dissociation of ${\mathrm{PCl}}_{5}$ is___$\times {10}^{-3}$. (nearest integer) (Given: $R=0.082L$ atm ${K}^{-1}{\mathrm{mol}}^{-1}$; Assume ideal gas behaviour)

The half life for the decomposition of gaseous compound $A$ is $240s$ when the gaseous pressure was $500$ Torr initially. When the pressure was $250$ Torr, the half life was found to be $4.0\mathrm{min}$. The order of the reaction is _____ (Nearest integer)

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$ Assertion $A$ : The reduction of a metal oxide is easier if the metal formed is in liquid state than solid state. Reason $R$ : The value of ${\Delta G}^{\Theta }$ becomes more on negative side as entropy is higher in liquid state than solid state. In the light of the above statements. Choose the most appropriate answer from the options given below

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$. Assertion $A$ :Phenolphthalein is a $\mathrm{pH}$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium Reason $R$ : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium. In the light of the above statements, choose the most appropriate answer from the options given below

$4.0$ moles of argon and $5.0$ moles of ${\mathrm{PCl}}_{5}$ are introduced into an evacuated flask of $100$ litre capacity at $610K$. The system is allowed to equilibrate. At equilibrium, the total pressure of mixture was found to be $6.0\mathrm{atm}$. The ${K}_{p}$ for the reaction is [Given : $R=0.082L$ atm ${K}^{-1}{\mathrm{mol}}^{-1}$ ]

Which of the following statements are correct? (A) The electronic configuration of $\mathrm{Cr}$ is $[\mathrm{Ar}]3{d}^{5}4{s}^{1}$. (B) The magnetic quantum number may have a negative value. (C) In the ground state of an atom, the orbitals are filled in order of their increasing energy order. (D) The total number of nodes are given by $n-2$. Choose the most appropriate answer from the options given below.

Given below are two statements. One is labelled as Assertion $A$ and the other is labelled as Reason $R$. Assertion $A$ : Energy of $2s$ orbital of hydrogen atom is greater than that of $2s$ orbital of lithium. Reason $R$ : Energies of the orbitals in the same subshell decrease with increase in the atomic number. In the light of the above statements, choose the correct answer from the options given below.

A protein '$A$' contains $0.30%$ of glycine (molecular weight $75$). The minimum molar mass of the protein '$A$' is____$\times {10}^{3}g{\mathrm{mol}}^{-1}$ [nearest integer]

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$ Assertion $A$ : Permanganate titration are not performed in presence of hydrochloric acid. Reason $R$ : Chlorine is formed as a consequence of oxidation of hydrochloric acid. In the light of the above statements, choose the correct answer from the options given below

Elevation in boiling point for $1.5$ molal solution of glucose in water is $4K$. The depression in freezing point for $4.5$ molal solution of glucose in water is $4K$. The ratio of molal elevation constant to molal depression constant $({K}_{b}/{K}_{f})$ is

The osmotic pressure of blood is $7.47$ bar at $300K$. To inject glucose to a patient intravenously, it has to be isotonic with blood. The concentration of glucose solution in ${\mathrm{gL}}^{-1}$ is (Molar mass of glucose $=180g{\mathrm{mol}}^{-1}$, $R=0.083{\mathrm{Lbar}}^{-1}{\mathrm{mol}}^{-1}$) (Nearest integer)

Identify the incorrect statement from the following.

For the reaction taking place in the cell: $\mathrm{Pt}(s){H}_{2}(g){H}^{+}(\mathrm{aq})||{\mathrm{Ag}}^{+}(\mathrm{aq})|\mathrm{Ag}(s)$ ${E}_{\mathrm{cell}}^{^{\circ}}=+0.5332V.$ The value of ${\Delta }_{f}{G}^{\ominus }$ is ${\mathrm{kJmol}}^{-1}$. (in nearest integer)

A compound '$X$' is a weak acid and it exhibits colour change at $\mathrm{pH}$ close to the equivalence point during neutralization of $\mathrm{NaOH}$ with ${\mathrm{CH}}_{3}\mathrm{COOH}$. Compound '$X$' exists in ionized form in basic medium. The compound '$X$' is

When $800\mathrm{mL}$ of $0.5M$ nitric acid is heated in a beaker, its volume is reduced to half and $11.5g$ of nitric acid is evaporated. The molarity of the remaining nitric acid solution is $x\times {10}^{-2}M$. (Molar mass of nitric acid is $63g{\mathrm{mol}}^{-1}$)

Match List - I with List - II. <table class="pyq-table"><tbody><tr><td></td><td>List-I</td><td></td><td>List-II</td></tr><tr><td>$(A)$</td><td>Spontaneous process</td><td>$(I)$</td><td>$\Delta H<0$</td></tr><tr><td>$(B)$</td><td>Process with $\Delta P=0,\Delta T=0$</td><td>$(\mathrm{II})$</td><td>${\Delta G}_{T,P}<0$</td></tr><tr><td>$(C)$</td><td>${\Delta H}_{\mathrm{reaction}}$</td><td>$(\mathrm{III})$</td><td>Isothermal and isobaric process</td></tr><tr><td>$(D)$</td><td>Exothermic Process</td><td>$(\mathrm{IV})$</td><td>[Bond energies of molecules in reactants] - [Bond energies of product molecules]</td></tr></tbody></table>Choose the correct answer from the options given below