NEET UG Chemistry — Physical Chemistry previous year questions with solutions.
Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?
A first order reaction has a rate constant of $2.303 \times 10^{-3} \mathrm{~s}^{-1}$. The time required for $40 \mathrm{~g}$ of this reactant to reduce to $10 \mathrm{~g}$ will be [Given that $\log _{10} 2=0.3010$ ]
Reversible expansion of an ideal gas under isothermal and adiabatic conditions are as shown in the figure.  $A B \rightarrow$ Isothermal expansion $A C \rightarrow$ Adiabatic expansion Which of the following option is not correct?
In water saturated air the mole fraction of water vapour is 0.02 . If the total pressure of the saturated air is $1.2 \mathrm{~atm}$, the partial pressure of dry air is
$4d, 5p, 5f$ and $6p$ orbitals are arranged in the order of decreasing energy. The correct option is:
In hydrogen atom, the de-Broglie wavelength of an electron in the second Bohr orbit is [Given that, Bohr radius, $\mathrm{a}_0=52.9 \mathrm{pm}$ ]
Which will make basic buffer?
For the cell reaction $2F{e}^{3+}(aq)+2{I}^{-}(aq)\rightarrow 2F{e}^{2+}(aq)+{I}_{2}(aq)$ ${E}_{cell}^{0}=0.24 V$ at $298 K.$ The standard Gibbs energy $({\Delta }_{r}{G}^{-})$ of the cell reaction is: [Given that Faraday constant $F=96500 Cmo{l}^{-1}$ ]
The $\mathrm{pH}$ of $0.01 \mathrm{M} \mathrm{NaOH}(a q)$ solution will be
An ideal gas expands isothermally from $10^{-3} \mathrm{~m}^3$ to $10^{-2} \mathrm{~m}^3$ at $300 \mathrm{~K}$ against a constant pressure of $10^5 \mathrm{Nm}^{-2}$. The work done on the gas is
Orbital having 3 angular nodes and 3 total nodes is
For a cell involving one electron ${E}_{cell}^{\circleddash }=0.59 V$ at $298 K$, the equilibrium constant for the cell reaction is: $[Given that \frac{2.303 RT}{F}=0.059 V at T=298 K]$
In which case change in entropy is negative?
pH of a saturated solution of $Ca{(OH)}_{2}$ is $9$ . The solubility product $({K}_{sp})$ of $Ca{(OH)}_{2}$ is:
Which of the following reactions are disproportionation reaction? $(a)$ $2C{u}^{+}\rightarrow C{u}^{2+}+C{u}^{0}$ $(b)$ $3Mn{O}_{4}^{2-}+4{H}^{+}\rightarrow 2Mn{O}_{4}^{-}+Mn{O}_{2}+2{H}_{2}O$ $(c)$ $2KMn{O}_{4}\overset{\Delta }{\rightarrow }{K}_{2}Mn{O}_{4}+Mn{O}_{2}+{O}_{2}$ $(d)$ $2Mn{O}_{4}^{-}+3M{n}^{2+}+2{H}_{2}O\rightarrow 5Mn{O}_{2}+4{H}^{\oplus }$ Select the correct option from the following:
For a reaction, activation energy $\mathrm{E}_{\mathrm{a}}=0$ and the rate constant at $200 \mathrm{~K}$ is $1.6 \times 10^6 \mathrm{~s}^{-1}$. The rate constant at $400 \mathrm{~K}$ will be [Given that gas constant $\mathrm{R}=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ ]
The bond dissociation energies of ${X}_{2} {Y}_{2}$ and $\mathrm{XY}$ are in the ratio of $1 :0.5 :1.\Delta H$ for the formation of $\mathrm{XY}$ is $-200\mathrm{kJ} {\mathrm{mol}}^{-1}$. What will be the bond dissociation energy of ${X}_{2}$?
In which case the number of molecules of water maximum?
Which one of the following conditions will favor the maximum formation of the product in the reaction? ${A}_{2}(g)+{B}_{2}(g)\rightleftharpoons {X}_{2}(g){\Delta }_{r}H=-X \mathrm{kJ}$
Following solutions were prepared by mixing different volumes of $\mathrm{NaOH}$ and $\mathrm{HCl}$ of different concentrations. (i) $60 \mathrm{mL}\frac{M}{10} \mathrm{HCl}+40\mathrm{mL}\frac{M}{10}\mathrm{NaOH}$ (ii) $55 \mathrm{mL}\frac{M}{10}\mathrm{HCl}+45\mathrm{mL}\frac{M}{10}\mathrm{NaOH}$ (iii) $75 \mathrm{mL}\frac{M}{5}\mathrm{HCl}+25\mathrm{mL}\frac{M}{5}\mathrm{NaOH}$ (iv) $100 \mathrm{mL}\frac{M}{10}\mathrm{HCl}+100 \mathrm{mL}\frac{M}{10}\mathrm{NaOH}$ The $\mathrm{pH}$ of which one of them will be equal to $1$?
When initial concentration of the reactant is doubled, what happens to the half-life period of a zero order reaction?
What is the correct difference between first and second order reactions?
Which one is a wrong statement?
For the redox reaction: ${\mathrm{MnO}}_{4}^{-}+{C}_{2}{O}_{4}^{2-}+{H}^{+}\rightarrow {\mathrm{Mn}}^{2+}+{\mathrm{CO}}_{2}+{H}_{2}O$ What are the correct coefficients of the reactants for the balanced equation?