Physical Chemistry PYQ — Page 47

These are physical properties of an element (A) Sublimation enthalpy (B) Ionisation enthalpy (C) Hydration enthalpy (D) Electron gain enthalpy The total number of above properties that affect the reduction potential is (Integer answer)

When $3.00g$ of a substance $X$' is dissolved in $100g$ of ${\mathrm{CCl}}_{4}$, it raises the boiling point by $0.60K$. The molar mass of the substance ' ${X}^{'}$ is ___ g ${\mathrm{mol}}^{-1}$. (Nearest integer). [Given ${K}_{b}$ for ${\mathrm{CCl}}_{4}$ is $5.0K\mathrm{kg}{\mathrm{mol}}^{-1}]$

The exact volumes of $1M\mathrm{NaOH}$ solution required to neutralise $50\mathrm{mL}$ of $1M{H}_{3}{\mathrm{PO}}_{3}$ solution and $100\mathrm{mL}$ of $2M{H}_{3}{\mathrm{PO}}_{2}$ solution, respectively, are :

The stepwise formation of ${[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{4}]}^{2+}$ is given below: ${\mathrm{Cu}}^{2+}+{\mathrm{NH}}_{3}\overset{{K}_{1}}{\rightleftharpoons }{[\mathrm{Cu}({\mathrm{NH}}_{3})]}^{2+}$ ${[\mathrm{Cu}({\mathrm{NH}}_{3})]}^{2+}+{\mathrm{NH}}_{3}\overset{{K}_{2}}{\rightleftharpoons }{[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{2}]}^{2+}$ ${[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{2}]}^{2+}+{\mathrm{NH}}_{3}\overset{{K}_{3}}{\rightleftharpoons }{[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{3}]}^{2+}$ ${[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{3}]}^{2+}+{\mathrm{NH}}_{3}\overset{{K}_{4}}{\rightleftharpoons }{[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{4}]}^{2+}$ The value of stability constants ${K}_{1},{K}_{2},{K}_{3}$ and ${K}_{4}$ are ${10}^{4},1.58\times {10}^{3},5\times {10}^{2}$ and ${10}^{2}$ respectively. The overall equilibrium constants for dissociation of ${[\mathrm{Cu}{({\mathrm{NH}}_{3})}_{4}]}^{2+}$ is $x\times {10}^{-12}.$ The value of $x$ is _____ (Rounded off to the nearest integer)

$200\mathrm{mL}$ of $0.2M\mathrm{HCl}$ is mixed with $300\mathrm{mL}$ of $0.1M\mathrm{NaOH}.$ The molar heat of neutralization of this reaction is $-57.1\mathrm{kJ}.$ The increase in temperature in $C\circ$ of the system on mixing is $x\times {10}^{-2}.$ The value of $x$ is (Nearest integer) [Given: Specific heat of water $=4.18J{g}^{-1}{K}^{-1}$ Density of water$=1.00g{\mathrm{cm}}^{-3}$] (Assume no volume change on mixing)

The Born-Haber cycle for $\mathrm{KCl}$ is evaluated with the following data: ${\Delta }_{f}{H}^{\Theta }\text{ for }\mathrm{KCl}=-436.7{\mathrm{kJmol}}^{-1};{\Delta }_{\mathrm{sub}}{H}^{\Theta }\text{ for }K=89.2{\mathrm{kJmol}}^{-1};$ ${\Delta }_{\text{ionization }}{H}^{\Theta }\text{ for }K=419.0\mathrm{kJ}{\text{ mol }}^{-1};{\Delta }_{\text{electron gain }}{H}^{\Theta }\text{ for }{\mathrm{Cl}}_{(g)}=-348.6{\mathrm{kJmol}}^{-1}$ ${\Delta }_{\text{bond }}{H}^{\Theta }\text{ for }{\mathrm{Cl}}_{2}=243.0{\mathrm{kJmol}}^{-1}$ The magnitude of lattice enthalpy of $\mathrm{KCl}$ in ${\mathrm{kJmol}}^{-1}$ is (Nearest integer)

$1.86g$ of aniline completely reacts to form acetanilide. $10%$ of the product is lost during purification. Amount of acetanilide obtained after purification (in $g$) is ___________ $\times {10}^{-2}.$

Complete combustion of $750g$ of an organic compound provides $420g$ of ${\mathrm{CO}}_{2}$ and $210g$ of ${H}_{2}O$. The percentage composition of carbon and hydrogen in organic compound is $15.3$ and ______ respectively. (Round off to the Nearest Integer)

The reaction rate for the reaction ${[{\mathrm{PtCl}}_{4}]}^{2-}+{H}_{2}O\rightleftharpoons {[\mathrm{Pt}({H}_{2}O){\mathrm{Cl}}_{3}]}^{-}+{\mathrm{Cl}}^{-}$ was measured as a function of concentrations of different species. It was observed that $\frac{-d[{[{\mathrm{PtCl}}_{4}]}^{2-}]}{\mathrm{dt}}=4.8\times {10}^{-5}[{[{\mathrm{PtCl}}_{4}]}^{2-}]-2.4\times {10}^{-3}[{[\mathrm{Pt}({H}_{2}O){\mathrm{Cl}}_{3}]}^{-}][{\mathrm{Cl}}^{-}]$ where square brackets are used to denote molar concentrations. The equilibrium constant ${K}_{c}=X$(Nearest integer) Value of $\frac{1}{X}is$ (question is modified.)

The plots of radial distribution functions for various orbitals of hydrogen atom against ' $r'$ are given below.The correct plot for $3s$ orbital is :

$\mathrm{Ge}(Z=32)$ in its ground state electronic configuration has $x$ completely filled orbitals with ${m}_{l}=0.$ The value of $x$ is __________ .

Consider the following reaction ${\mathrm{MnO}}_{4}^{-}+8{H}^{+}+5{e}^{-}\rightarrow {\mathrm{Mn}}^{+2}+4{H}_{2}O,E^{\circ}=1.51V$ The quantity of electricity required in Faraday to reduce five moles of ${\mathrm{MnO}}_{4}^{-}$ is

Which one of the following $0.06M$ aqueous solutions has lowest freezing point ?

For a reaction of order $n,$ the unit of the rate constant is :

For the reaction $A+B\rightleftharpoons 2C$ the value of equilibrium constant is $100$ at $298K$. If the initial concentration of all the three species is $1M$ each, then the equilibrium concentration of $C$ is $x\times {10}^{-1}M$. The value of $x$ is _______. (Nearest integer)

The solubility of ${\mathrm{CdSO}}_{4}$ in water is $8.0\times {10}^{-4}\mathrm{mol}{L}^{-1}$. Its solubility in $0.01M{H}_{2}{\mathrm{SO}}_{4}$ solution is ___ $\times {10}^{-6}\mathrm{mol}{L}^{-1}$ (Round off to the Nearest integer) (Assume that solubility is much less than $0.01M$ )

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $\frac{{h}^{2}}{x{\mathrm{ma}}_{0}^{2}}.$ The value of $10x$ is (${a}_{0}$ is radius of Bohr's orbit) (Nearest integer) [Given: $\pi =3.14$]

(A) $\mathrm{HOCl}+{H}_{2}{O}_{2}\rightarrow {H}_{3}{O}^{+}+{\mathrm{Cl}}^{-}+{O}_{2}$ (B) ${I}_{2}+{H}_{2}{O}_{2}+2{\mathrm{OH}}^{-}\rightarrow 2{I}^{-}+2{H}_{2}O+{O}_{2}$ Choose the correct option.

The value of magnetic quantum number of the outermost electron of ${\mathrm{Zn}}^{+}$ ion is _________ . (Integer answer)

A certain orbital has no angular nodes and two radial nodes. The orbital is:

A $50$ watt bulb emits monochromatic red light of wavelength of $795\mathrm{nm}$. The number of photons emitted per second by the bulb is $x\times {10}^{20}.$ The value of $x$ is _____ . (Nearest integer) $\text{ [Given : }h=6.63\times {10}^{-34}\mathrm{Js}\text{ and}c=3.0\times {10}^{8}{\mathrm{ms}}^{-1}]$

Which of the following compound CANNOT act as a Lewis base?

${N}_{2}{O}_{5(g)}\rightarrow 2{\mathrm{NO}}_{2(g)}+\frac{1}{2}{O}_{2(g)}$ In the above first order reaction the initial concentration of ${N}_{2}{O}_{5}$ is $2.40\times {10}^{-2}\mathrm{mol}{L}^{-1}$ at $318K.$ The concentration of ${N}_{2}{O}_{5}$ after $1$ hour was $1.60$$\times {10}^{-2}\mathrm{mol}{L}^{-1}.$ The rate constant of the reaction at $318K$ is $\times {10}^{-3}{\mathrm{min}}^{-1}$ (Nearest integer): $[$ Given $:\mathrm{log}3=0.477,\mathrm{log}5=0.699]$

$0.4g$ mixture of $\mathrm{NaOH},{\mathrm{Na}}_{2}{\mathrm{CO}}_{3}$ and some inert impurities was first titrated with $\frac{N}{10}\mathrm{HCl}$ using phenolphthalein as an indicator, $17.5\mathrm{mL}$ of $\mathrm{HCl}$ was required at the end point. After this methyl orange was added and titrated. $1.5\mathrm{mL}$ of same $\mathrm{HCl}$ was required for the next end point. The weight percentage of ${\mathrm{Na}}_{2}{\mathrm{CO}}_{3}$ in the mixture is (Rounded-off to the nearest integer)