JEE Main Chemistry — Physical Chemistry previous year questions with solutions.
Two Faraday of electricity is passed through a solution of $CuS{O}_{4}$ . The mass of copper deposited at the cathode is: (Atomic mass of Cu = 63.5 amu)
A variable, the opposite external potential $({E}_{\mathrm{ext}})$ is applied to the cell $Zn | Z{n}^{2+} (1M)\parallel C{u}^{2+} (1 M)| Cu$, of potential $1.1V$. When ${E}_{ext}<1.1 V$ and ${E}_{ext}>1.1 V$, respectively electrons flow from
The molecular formula of a commercial resin used for exchanging ions in water softening is ${C}_{8}{H}_{7}S{O}_{3}Na$ $(\mathrm{molecular}\mathrm{weight}=206)$. What would be the maximum uptake of $C{a}^{2+}$ ions by the resin if expressed in $\mathrm{mol}$ per $\mathrm{gm}$?
The vapour pressure of acetone at ${20}^{o}C$ is $185\mathrm{torr}$. When $1.2g$ of a non-volatile substance was dissolved in $100g$ of acetone at ${20}^{o}C$ , its vapour pressure was $183\mathrm{torr}$. The molar mass $(g mo{l}^{-1})$ of the substance is:
At temperature $T$, the average kinetic energy of any particle is $\frac{3}{2}\mathrm{kT}$. The de Broglie wavelength follows the order:
Determination of the molar mass of acetic acid in benzene using freezing point depression is affected by:
The following reaction is performed at $298K$. $2NO(g)+{O}_{2}(g)\rightleftharpoons 2N{O}_{2}(g)$ The standard free energy of the formation of $NO(g)$ is $86.6\mathrm{kJ}{\mathrm{mol}}^{-1}$ at $298K$. What is the standard free energy of the formation of $N{O}_{2}(g)$ at $298K$? $({K}_{P}=1.6\times {10}^{12})$
At $298K$, the standard reduction potentials are $1.51V$ for ${MnO}_{4}^{-} | M{n}^{2+}$, $1.36V$ for $C{l}_{2}|C{l}^{-}$, $1.07V$ for $B{r}_{2}|B{r}^{-}$, $0.54V$ for ${I}_{2}|{I}^{-}$. At $\mathrm{pH}=3$, permanganate is expected to oxidize: $(\frac{RT}{F}=0.059)$
If the principal quantum number $\text{n}=6,$ the correct sequence of filling of electrons will be:
A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed. The dried sample weighed 52 g. The formula of the hydrated salt is: (atomic mass, Ba = 137 amu, Cl = 35.5 amu)
The half-life period of a first-order reaction is $15\text{minutes}$. The amount of substance left after one hour will be
Consider the following equilibrium $$ \mathrm{AgCl} \downarrow+2 \mathrm{NH}_3 \rightleftharpoons\left[\mathrm{Ag}\left(\mathrm{NH}_3 2_2\right]^{+}+\mathrm{Cl}^{-}\right. $$ White precipitate of $\mathrm{AgCl}$ appears on adding which of the following?
Based on the equation: $$ \Delta \mathrm{E}=-2.0 \times 10^{-18} \mathrm{~J}\left(\frac{1}{\mathrm{n}_2^2}-\frac{1}{\mathrm{n}_1^2}\right) $$ the wavelength of the light that must be absorbed to excite hydrogen electron from level $n=1$ to level $\mathrm{n}=2$ will be: $\left(\mathrm{h}=6.625 \times 10^{-34} \mathrm{Js}, \mathrm{C}=3 \times 10^8 \mathrm{~ms}^{-1}\right)$
The correct set of four quantum numbers for the valence electrons of rubidium atom $(Z=37)$ is
At a certain temperature, only 50% HI is dissociated into H$_{2}$ and I$_{2}$ at equilibrium. The equilibrium constant is :
The molar heat capacity $\left(\mathrm{C}_{\mathrm{p}}\right)$ of $\mathrm{CD}_2 \mathrm{O}$ is 10 cals at $1000 \mathrm{~K}$. The change in entropy associated with cooling of $32 \mathrm{~g}$ of $\mathrm{CD}_2 \mathrm{O}$ vapour from $1000 \mathrm{~K}$ to $100 \mathrm{~K}$ at constant pressure will be: $(\mathrm{D}=$ deuterium, atomic mass $=2 \mathrm{u})$
The conjugate base of hydrazoic acid is:
The standard electrode potentials $( {\text{E}}_{ {\text{M}}^{+} / \text{M} }^{\text{o}} )$ of four metals $\text{A,} \text{B,} \text{C}$ and $\text{D}$ are $-\text{1}\text{.2} \text{V,}$$\text{0}\text{.6} \text{V}$, $\text{0}\text{.85} \text{V}$ and $-\text{0}\text{.76} \text{V}$, respectively. The sequence of deposition of metals on applying potential is
For an ideal solution of two components $A&B$, which of the following is true?
The standard enthalpy of formation $\left(\Delta_f \mathrm{H}^{\circ}{ }_{298}\right)$ for methane, $\mathrm{CH}_4$ is $-74.9 \mathrm{~kJ} \mathrm{~mol}^{-1}$. In order to calculate the average energy given out in the formation of a $\mathrm{C}-\mathrm{H}$ bond from this it is necessary to know which one of the following?
For the decomposition of the compound, represented as ${\text{NH}}_{2} {\text{COONH}}_{4} ( \text{s} ) \rightleftharpoons 2 {\text{NH}}_{3} ( \text{g} ) + {\text{CO}}_{2} ( \text{g} )$ the ${K}_{p}=2.9\times {10}^{-5}{atm}^{3}$. If the reaction is started with 1 mole of the compound, the total pressure at equilibrium would be :
The rate coefficient $(k)$ for a particular reactions is $1.3 \times 10^{-4} \mathrm{M}^{-1} \mathrm{~s}^{-1}$ at $100^{\circ} \mathrm{C}$, and $1.3 \times 10^{-3}$ $\mathrm{M}^{-1} \mathrm{~s}^{-1}$ at $150^{\circ} \mathrm{C}$. What is the energy of activation $\left(\mathrm{E}_{\mathrm{A}}\right)$ (in $\left.\mathrm{kJ}\right)$ for this reaction? $(\mathrm{R}=$ molar gas constant $=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ )
The amount of $\mathrm{BaSO}_4$ formed upon mixing 100 $\mathrm{mL}$ of $20.8 \% \mathrm{BaCl}_2$ solution with $50 \mathrm{~mL}$ of $9.8 \%$ $\mathrm{H}_2 \mathrm{SO}_4$ solution will be: $(\mathrm{Ba}=137, \mathrm{Cl}=35.5, \mathrm{~S}=32, \mathrm{H}=1$ and $\mathrm{O}=16$ )
The ionization energy of gaseous $\mathrm{Na}$ atoms is $495.5\mathrm{kJ}{\mathrm{mol}}^{-1}$. The lowest possible frequency of light that ionizes a sodium atom is $(\text{h}=\text{6.626}\times 1{0}^{-34}Js,{N}_{\text{A}}=\text{6.022}\times 1{0}^{23}{mol}^{-1})$