Physical Chemistry PYQ — Page 42

$100\mathrm{mL}$ 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 : $C=12.0u,H:1.0u,O:16.0u,\mathrm{Br}=80.0u$]

The ${\mathrm{NaNO}}_{3}$ weighed out to make $50\mathrm{mL}$ of an aqueous solution containing $70.0\mathrm{mg}{\mathrm{Na}}^{+}$ per $\mathrm{mL}$ is_ $g$. (Rounded off to the nearest integer) [Given : Atomic weight in ${\mathrm{gmol}}^{-1}-\mathrm{Na}:23;N:14;O:16$]

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

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 $:R=8.3J{\mathrm{mol}}^{-1}{K}^{-1}]$

The spin only magnetic moments (in BM) for free ${\mathrm{Ti}}^{3+},{V}^{2+}$ and ${\mathrm{Sc}}^{3+}$ ions respectively are (At.No. $\mathrm{Sc}$ : $21,\mathrm{Ti}:22,V:23$ )

The number of orbitals with $n=5,{m}_{1}=+2$ is ________. (Round off to the Nearest Integer).

A ball weighing $10g$ is moving with a velocity of $90m{s}^{-1}.$ If the uncertainty in its velocity is $5%$, then the uncertainty in its position is _ $\times {10}^{-33}m.$ (Rounded off to the nearest integer) [Given: $h=6.63\times {10}^{-34}\mathrm{Js}$]

A proton and a ${\mathrm{Li}}^{3+}$ nucleus are accelerated by the same potential. If ${\lambda }_{\mathrm{Li}}$ and ${\lambda }_{p}$ denote the de Broglie wavelengths of ${\mathrm{Li}}^{3+}$ and proton respectively, then the value of $\frac{{\lambda }_{\mathrm{Li}}}{{\lambda }_{p}}$ is $x\times {10}^{-1}$. The value of $x$ is _____ (Rounded off to the nearest integer) [Mass of ${\mathrm{Li}}^{3+}=8.3$ mass of proton]

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 $1990K$ and $1\mathrm{atm}$ pressure, there are equal number of ${\mathrm{Cl}}_{2}$ molecules and $\mathrm{Cl}$ atoms in the reaction mixture. The value of ${K}_{p}$ for the reaction ${\mathrm{Cl}}_{2(g)}=2{\mathrm{Cl}}_{(g)}$ under the above conditions is $x\times {10}^{-1}.$ The value of $x$ is______(Rounded off to the nearest integer)

For the reaction $A(g)\rightleftharpoons B(g)$ at $495K$, ${\Delta }_{r}{G}^{^{\circ}}=-9.478\mathrm{kJ}{\mathrm{mol}}^{-1}$ If we start the reaction in a closed container at $495K$ with $22$ millimoles of $A$, the amount of $B$ is the equilibrium mixture is ________ millimoles. (Round off to the Nearest Integer). $[R=8.314J{\mathrm{mol}}^{-1}{K}^{-1};\ell n10=2.303]$

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 $=1.0g{\mathrm{cm}}^{-3}]$

When $12.2g$ of benzoic acid is dissolved in $100g$ of water, the freezing point of solution was found to be $-0.93^{\circ}C({K}_{f}({H}_{2}O)=1.86K\mathrm{kg}{\mathrm{mol}}^{-1})$. The number $(n)$ of benzoic acid molecules associated (assuming $100%$ association) is _.

$250\mathrm{mL}$ of $0.5M\mathrm{NaOH}$ was added to $500\mathrm{mL}$ of $1M$ $\mathrm{HCl}$. The number of unreacted $\mathrm{HCl}$ molecules in the solution after the complete reaction is p$\times {10}^{21}$. Find out p (Nearest integer) $({N}_{A}=6.022\times {10}^{23})$

Methylation of $10g$ of benzene gave $9.2g$ of toluene. Calculate the percentage yield of toluene (Nearest integer)

The oxidation states of $'P'$ in ${H}_{4}{P}_{2}{O}_{7},{H}_{4}{P}_{2}{O}_{5}$ and ${H}_{4}{P}_{2}{O}_{6},$ respectively, are :

${\mathrm{Cu}}^{2+}$ salt reacts with potassium iodide to give

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

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) $[R=0.08206{\mathrm{dm}}^{3}\mathrm{atm}{K}^{-1}{\mathrm{mol}}^{-1}]$

A certain orbital has $n=4$ and ${m}_{l}=-3.$ The number of radial nodes in this orbital is _______. (Round off to the Nearest Integer).

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).

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: ${\mathrm{log}}_{10}2=0.301,\mathrm{ln}10=2.303$]