NEET UG Chemistry — Physical Chemistry previous year questions with solutions.
Consider the change in oxidation state of Bromine corresponding to different emf values, as shown in the diagram below:  Then, what is the species undergoing disproportionation?
The solubility of ${\mathrm{BaSO}}_{4}$ in water is $2.42\times {10}^{-3}{\mathrm{gL}}^{-1}$ at $298 K.$ The value of its solubility product $({K}_{\mathrm{sp}})$ will be (Given- the molar mass of ${\mathrm{BaSO}}_{4}=233 g {\mathrm{mol}}^{-1}$)
A mixture of $2.3g$ formic acid and $4.5g$ oxalic acid is treated with concentrate ${H}_{2}{\mathrm{SO}}_{4}$. The evolved gaseous mixture is passed through $\mathrm{KOH}$ pellets. What will be the weight in grams of the remaining product at $\mathrm{STP}$?
For a given reaction, $\text{Δ}\text{H}=35.5 \text{k}\text{J} \text{m}\text{o}{\text{l}}^{-1}$ and $\text{Δ}\text{S}=83.6 \text{J}{\text{K}}^{-1}\text{m}\text{o}{\text{l}}^{-1}.$ The reaction is spontaneous at : (Assume that $\text{Δ}\text{H}$ and $\text{Δ}\text{S}$ do not vary with temperature)
Which one of the following statements is not correct?
A first-order reaction has a specific reaction rate ${10}^{-2}{\mathrm{sec}}^{-1}.$ How much time will it take for $20g$ the reactant to reduce to $5g$?
The equilibrium constants of the following are: $\begin{matrix}{N}_{2}+3{H}_{2}\rightleftharpoons 2 {\mathrm{NH}}_{3} & {K}_{1} \\ {N}_{2}+{O}_{2}\rightleftharpoons 2 \mathrm{NO} & {K}_{2} \\ {H}_{2}+\frac{1}{2}{O}_{2}\rightarrow {H}_{2}O & {K}_{3}\end{matrix}$ The equilibrium constant ($K$) of the reaction: $2NH{}_{3}+\frac{5}{2}O{}_{2}\overset{K}{\rightleftharpoons }2NO+3H{}_{2}O$, will be:
Which one of the following statements is wrong?
Which of the following is dependent on temperature?
Concentration of the ${\mathrm{Ag}}^{+}$ ions in a saturated solution of ${\mathrm{Ag}}_{2}{C}_{2}{O}_{4}$ is $2.2\times {10}^{-4} \mathrm{mol} {L}^{-1}.$ Solubility product of ${\mathrm{Ag}}_{2}{C}_{2}{O}_{4}$ is
Mechanism of a hypothetical reaction ${X}_{2}+{Y}_{2}\rightarrow 2\mathrm{XY}$ is given below: (i) ${X}_{2}\rightarrow X+X (\mathrm{fast})$ (ii) $X+{Y}_{2}\rightleftharpoons \mathrm{XY}+Y(\mathrm{slow})$ (iii) $X+Y\rightarrow \mathrm{XY} (\mathrm{fast})$ The overall order of the reaction will be
In the electrochemical cell: $\mathrm{Zn}|{\mathrm{ZnSO}}_{4}(0.01M)||{\mathrm{CuSO}}_{4}(1.0 M)|\mathrm{Cu},$ the emf of this Daniel cell is ${E}_{1}$ . When the concentration ${\mathrm{ZnSO}}_{4}$ is changed to $1.0M$ and that of ${\mathrm{CuSO}}_{4}$ changed to $0.01M,$ the emf changes to ${E}_{2}$ . From the following, which one is the relationship between ${E}_{1}$ and ${E}_{2}$? (Given, $\frac{\mathrm{RT}}{F}=0.059$)
If molality of the dilute solution is doubled, the value of molal depression constant $({K}_{f})$ will be
A gas is allowed to expand in a well-insulated container against a constant external pressure of$2.5\mathrm{atm}$ from an initial volume of $2.50L$ to a final volume of $4.50L.$ The change in internal energy $\Delta U$ of the gas in joules will be
For a sample of perfect gas, when its pressure is changed isothermally from ${p}_{i}$ to ${p}_{f}$, the entropy change is given by
The molar conductivity of a $0.5\mathrm{mol}{\mathrm{dm}}^{-3}$ solution of $AgN{O}_{3}$ with electrolytic conductivity of $5.76\times {10}^{-3}S c{m}^{-1}$ at $298K$
At ${100}^{o}C$ the vapour pressure of a solution of 6.5 g of a non-volatile solute in 100 g water is 732 mm. If ${K}_{b}=0.52$ , the boiling point of this solution will be:
Which one of the following is incorrect for ideal solution?
The decomposition of phosphine $(P{H}_{3})$ on tungsten at low pressure is a first-order reaction. It is because the
Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because
The rate of a first-order reaction is $0.04 mol {l}^{-1}{s}^{-1}$ at $10$ second and $0.03 mol {l}^{-1}{s}^{-1}$ at $20$ seconds after initiation of the reaction. The half-life period of the reaction is:
The van't Hoff factor $(i)$ for a dilute aqueous solution of the strong electrolyte barium hydroxide is
The number of electrons delivered at the cathode, during electrolysis by a current of $1\mathrm{ampere}\mathrm{in}60\mathrm{seconds}$ is (charge on electron $=1.60\times {10}^{-19} C$)
Two electrons occupying the same orbital are distinguished by: