JEE Main Chemistry — Physical Chemistry previous year questions with solutions.
What happens to freezing point of benzene when small quantity of napthalene is added to benzene?
The ratio \(\frac{K_P}{K_C}\) for the reaction : \(\mathrm{CO}_{(\mathrm{g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons \mathrm{CO}_{2(\mathrm{~g})}\) is :
The solution from the following with highest depression in freezing point/lowest freezing point is
A constant current was passed through a solution of ${\mathrm{AuCl}}_{4}^{-}$ ion between gold electrodes. After a period of $10.0$ minutes, the increase in mass of cathode was $1.314g$. The total charge passed through the solution is ___$\times {10}^{-2}F$. (Given atomic mass of $\mathrm{Au}=197)$
Which of the following is not correct?
Time required for completion of $99.9%$ of first order reaction is ________ times of half life $({t}_{1/2})$ of the reaction
The mass of silver (Molar mass of $\mathrm{Ag}:108{\mathrm{gmol}}^{-1}$ ) displaced by a quantity of electricity which displaces $5600\mathrm{mL}$ of ${O}_{2}$ at S.T.P. will be _____ g.
Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following :
A sample of ${\mathrm{CaCO}}_{3}$ and ${\mathrm{MgCO}}_{3}$ weighed $2.21g$ is ignited to constant weight of $1.152g$. The composition of the mixture is: (Given molar mass in $g{\mathrm{mol}}^{-1}$, ${\mathrm{CaCO}}_{3}:100,{\mathrm{MgCO}}_{3}:84$)
Integrated rate law equation for a first order gas phase reaction is given by (where ${P}_{i}$ is initial pressure and ${P}_{t}$ is total pressure at time $t$)
Three moles of an ideal gas are compressed isothermally from \(60 \mathrm{~L}\) to \(20 \mathrm{~L}\) using constant pressure of \(5 \mathrm{~atm}\). Heat exchange \(\mathrm{Q}\) for the compression is - ______ Lit. atm.
The ratio of $\frac{C14}{C12}$ in a piece of wood is $\frac{1}{8}$ part that of atmosphere. If half life of $C14$ is $5730$ years, the age of wood sample is ..... years.
The mass of sodium acetate $({\mathrm{CH}}_{3}\mathrm{COONa})$ required to prepare $250\mathrm{mL}$ of $0.35M$ aqueous solution is _____ g.$($ Molar mass of ${\mathrm{CH}}_{3}\mathrm{COONa}$ is $82.02g{\mathrm{mol}}^{-1}$) Round off to the nearest integer.
Among the following halogens \(\mathrm{F}_2, \mathrm{Cl}_2, \mathrm{Br}_2\) and \(\mathrm{I}_2\) Which can undergo disproportionation reactions?
The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' \(\mathrm{A}\) ' \(\times 10^{12}\) hertz and that has a radiant intensity in that direction of \(\frac{1}{'\mathrm{~B}^{\prime}}\) watt per steradian. 'A' and 'B' are respectively
The incorrect postulates of the Dalton's atomic theory are : (A) Atoms of different elements differ in mass. (B) Matter consists of divisible atoms. (C) Compounds are formed when atoms of different element combine in a fixed ratio. (D) All the atoms of given element have different properties including mass. (E) Chemical reactions involve reorganisation of atoms. Choose the correct answer from the options given below :
If three moles of an ideal gas at $300K$ expand isothermally from $30{\mathrm{dm}}^{3}$ to $45{\mathrm{dm}}^{3}$ against a constant opposing pressure of $80\mathrm{kPa}$, then the amount of heat transferred is __________J.
$4.5$ moles each of hydrogen and iodine is heated in a sealed ten litre vessel.At equilibrium, $3$ moles of $\mathrm{HI}$ were found. The equilibrium constant for ${H}_{2}(g)+{I}_{2}(g)\rightleftharpoons 2{\mathrm{HI}}_{(g)}$ is ........
The wave function $(\Psi )$ of $2s$ is given by ${\Psi }_{2s}=\frac{1}{2\sqrt{2\pi }}{(\frac{1}{{a}_{0}})}^{1/2}(2-\frac{r}{{a}_{0}}){e}^{-r/2{a}_{0}}$ At $r={r}_{0}$, radial node is formed. Thus, ${r}_{0}$ in terms of ${a}_{0}$
The equilibrium composition for the reaction ${\mathrm{PCl}}_{3}+{\mathrm{Cl}}_{2}\underset{}{\rightleftharpoons }{\mathrm{PCl}}_{5}$ at $298K$ is given below: ${[{\mathrm{PCl}}_{3}]}_{\mathrm{eq}}=0.2\mathrm{mol}{L}^{-1},{[{\mathrm{Cl}}_{2}]}_{\mathrm{eq}}=0.1\mathrm{mol}{L}^{-1},{[{\mathrm{PCl}}_{5}]}_{\mathrm{eq}}=0.40\mathrm{mol}{L}^{-1}$ If $0.2\mathrm{mol}$ of ${\mathrm{Cl}}_{2}$ is added at the same temperature, the equilibrium concentrations of ${\mathrm{PCl}}_{5}$ is _____ $\times {10}^{–2}\mathrm{mol}{L}^{–1}$ Given: ${K}_{c}$ for the reaction at $298K$ is $20$
$A(g)\rightarrow 2B(g)+C(g)$ is a first order reaction. The initial pressure of the system was found to be $800\mathrm{mm}\mathrm{Hg}$ which increased to $1600\mathrm{mm}\mathrm{Hg}$ after $10\mathrm{min}$. The total pressure of the system after $30$min will be $\mathrm{mm}\mathrm{Hg}$. (Nearest integer)
Some amount of dichloromethane $({\mathrm{CH}}_{2}{\mathrm{Cl}}_{2})$ is added to $671.141\mathrm{mL}$ of chloroform $({\mathrm{CHCl}}_{3})$ to prepare $2.6\times {10}^{-3}M$ solution of ${\mathrm{CH}}_{2}{\mathrm{Cl}}_{2}(\mathrm{DCM})$. The concentration of $\mathrm{DCM}$ is _____ ppm (by mass). Given: Atomic mass : $C=12;H:1;\mathrm{Cl}=35.5$ density of ${\mathrm{CHCl}}_{3}=1.49g{\mathrm{cm}}^{-3}$
The enthalpy change for the conversion of $\frac{1}{2}{\mathrm{Cl}}_{2}$ (g) to ${\mathrm{Cl}}^{-}(\mathrm{aq})$ is $(-)$ ${\mathrm{kJmol}}^{-1}$ (Nearest integer) Given : ${\Delta }_{\text{dis }}{H}_{{\mathrm{Cl}}_{2(g)}}^{0}=240{\mathrm{kJmol}}^{-1}$. ${\Delta }_{\mathrm{eg}}{H}_{\mathrm{Cl}(g)}^{o}=-350{\mathrm{kJmol}}^{-1}$, ${\Delta }_{\mathrm{hyd}}{H}_{{\mathrm{Cl}}_{(g)}^{-}}^{o}=-380{\mathrm{kJmol}}^{-1}$
What weight of glucose must be dissolved in $100g$ of water to lower the vapour pressure by $0.20\mathrm{mm}\mathrm{Hg}$? (Assume dilute solution is being formed) Given: Vapour pressure of pure water is $54.2\mathrm{mm}\mathrm{Hg}$ at room temperature.Molar mass of glucose is $180g{\mathrm{mol}}^{-1}$