Physical Chemistry PYQ — Page 42

Number of electrons that Vanadium $(Z=23)$ has in p-orbitals is equal to:

The species given below that does $\mathrm{NOT}$ show disproportionation reaction is:

For water ${\Delta }_{\mathrm{vap}}H=41\mathrm{kJ}{\mathrm{mol}}^{-1}$ at $373K$ and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is $({\mathrm{kJmol}}^{-1})$: [ Use $:R=8.3J{\mathrm{mol}}^{-1}{K}^{-1}]$

If the concentration of glucose $({C}_{6}{H}_{12}{O}_{6})$ in blood is $0.72g{L}^{-1},$ the molarity of glucose in blood is $-\times {10}^{-3}M$ (Nearest integer): $[$Given : Atomic mass of $C=12,H=1,O=16u]$

At $298K$, the enthalpy of fusion of a solid $(X)$ is $2.8\mathrm{kJ}{\mathrm{mol}}^{-1}$ and the enthalpy of vaporisation of the liquid $(X)$ is $98.2\mathrm{kJ}{\mathrm{mol}}^{-1}$. The enthalpy of sublimation of the substance $(X)$ in $\mathrm{kJ}{\mathrm{mol}}^{-1}$ is ______. (in nearest integer)

For the reaction ${C}_{2}{H}_{6}\rightarrow {C}_{2}{H}_{4}+{H}_{2}$ the reaction enthalpy ${\Delta }_{r}H\mathrm{in}$ ${\mathrm{kJmol}}^{-1}$ is (Round off to the Nearest Integer). [Given : Bond enthalpies in ${\mathrm{kJmol}}^{-1}:C-C:$ $347,C=C:611;C-H:414,H-H:436]$

The molarity of the solution prepared by dissolving $6.3g$ of oxalic acid $({H}_{2}{C}_{2}{O}_{4}\cdot 2{H}_{2}O)$ in $250\mathrm{mL}$ of water in $\mathrm{mol}{L}^{-1}$ is $x\times {10}^{-2}.$ The value of $x$ is _________ . (Nearest integer) [Atomic mass : $H:1.0,C:12.0,0:16.0J$]

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 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 ___________ $\times {10}^{-2}.$

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

Consider the reaction ${N}_{2}{O}_{4}(g)\rightleftharpoons 2{\mathrm{NO}}_{2}(g)$ The temperature at which ${K}_{C}=20.4$ and ${K}_{P}=600.1,$ is ______ $K$. (Round off to the Nearest Integer). [Assume all gases are ideal and $R=0.0831L$ bar ${K}^{-1}{\mathrm{mol}}^{-1}]$

The number of photons emitted by a monochromatic (single frequency) infrared range finder of power $1\mathrm{mW}$ and wavelength of $1000\mathrm{nm}$, in $0.1$ second is $x\times {10}^{13}$. The value of $x$ is (Nearest integer) $(h=6.63\times {10}^{-34}\mathrm{Js},c=3.00\times {10}^{8}{\mathrm{ms}}^{-1})$:

Dichromate ion is treated with base, the oxidation number of $\mathrm{Cr}$ in the product formed is

A homogeneous ideal gaseous reaction ${\mathrm{AB}}_{2(g)}\rightleftharpoons {A}_{(g)}+2{B}_{(g)}$ is carried out in a $25\mathrm{litre}$ flask at $27^{\circ}C$. The initial amount of ${\mathrm{AB}}_{2}$ was $1$ mole and the equilibrium pressure was $1.9\mathrm{atm}$. The value of ${K}_{p}$ is $x\times {10}^{-2}$. The value of $x$ is (Integer answer) $[R=0.08206{\mathrm{dm}}^{3}\mathrm{atm}{K}^{-1}{\mathrm{mol}}^{-1}]$

Two salts ${A}_{2}X$ and $\mathrm{MX}$ have the same value of solubility product of $4.0\times {10}^{-12}$. The ratio of their molar solubilizes i.e. $\frac{S({A}_{2}X)}{S(\mathrm{MX})}=$ ________. (Round off to the Nearest Integer).

(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.

An average person needs about $10000\mathrm{kJ}$ energy per day. The amount of glucose (molar mass $=180.0g{\mathrm{mol}}^{-1}$) needed to meet this energy requirement is ______$g.$ (Use : ${\Delta }_{C}H$ (glucose)$=-2700\mathrm{kJ}{\mathrm{mol}}^{-1}$)

For a certain first order reaction $32%$ of the reactant is left after $570s.$ The rate constant of this reaction is $\times {10}^{-3}{s}^{-1}.$ (Round off to the Nearest Integer). [Given: ${\mathrm{log}}_{10}2=0.301,\mathrm{ln}10=2.303$]

The equilibrium constant ${K}_{c}$ at $298K$ for the reaction $A+B\rightleftharpoons C+D$ is $100.$ Starting with an equimolar solution with concentrations of $A,B,C$ and $D$ all equal to $1M$, the equilibrium concentration of $D$ is _____$\times {10}^{-2}M$. (Nearest integer)

Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of $3.33h$ at $25^{\circ}C.$ After $9h,$ the fraction of sucrose remaining is $f.$ The value of ${\mathrm{log}}_{10}(\frac{1}{f})$ is ________ $\times {10}^{-2}.$ (Rounded off to the nearest integer) [Assume: In$10=2.303,\mathrm{ln}2=0.693$]

${\mathrm{PCl}}_{5}\rightleftharpoons {\mathrm{PCl}}_{3}+{\mathrm{Cl}}_{2}{K}_{c}=1.844$ $3.0$ moles of ${\mathrm{PCl}}_{5}$ is introduced in a $1L$ closed reaction vessel at $380K.$ The number of moles of ${\mathrm{PCl}}_{5}$ at equilibrium is $—\times {10}^{-3}$ (Round off to the Nearest Integer)

The oxidation states of nitrogen in $\mathrm{NO},{\mathrm{NO}}_{2},{N}_{2}O$ and ${\mathrm{NO}}_{3}^{-}$ are in the order of :

Sodium oxide reacts with water to produce sodium hydroxide. $20.0g$ of sodium oxide is dissolved in $500\mathrm{mL}$ of water. Neglecting the change in volume, the concentration of the resulting $\mathrm{NaOH}$ solution is _________ $\times {10}^{-1}M.$ (Nearest integer) [Atomic mass : $\mathrm{Na}=23.0,O=16.0,H=1.0$]