Chemistry Physical Chemistry questions from NEET UG 2022.
Find the emf of the cell in which the following reaction takes place at $298K$ $\mathrm{Ni}(s)+2{\mathrm{Ag}}^{+}(0.001M)\rightarrow {\mathrm{Ni}}^{2+}(0.001M)+2\mathrm{Ag}(s)$ (Given that $E{^{\circ}}_{\mathrm{cell}}=1.05V,\frac{2.303\mathrm{RT}}{F}=0.059$ at $298K$)
The $\mathrm{pH}$ of the solution containing $50\mathrm{mL}$ each of $0.10M$ sodium acetate and $0.01M$ acetic acid is [Given ${\mathrm{pK}}_{a}$ of ${\mathrm{CH}}_{3}\mathrm{COOH}=4.57$]
$3{O}_{2}(g)\rightleftharpoons 2{O}_{3}(g)$ for the above reaction at $298K,{K}_{c}$ is found to be $3.0\times {10}^{-59}$. If the concentration of ${O}_{2}$ at equilibrium is $0.040M$ then concentration of ${O}_{3}$ in $M$ is
Two half cell reactions are given below : $\mathrm{CO}^{3+}+\mathrm{e}^{-} \rightarrow \mathrm{Co}^{2+}, \mathrm{E}^{\circ} \mathrm{Co}^{2+} / \mathrm{Co}^{3+}=-1.81 \mathrm{~V}$ $2 \mathrm{Al}^{3+}+6 \mathrm{e}^{-} \rightarrow 2 \mathrm{Al}(\mathrm{s}), \mathrm{E}^{\mathrm{o}} \mathrm{Al} / \mathrm{Al}^{3+}=+1.66 \mathrm{~V}$ The standard EMF of a cell with feasible redox reaction will be :
Match List-I with List-II:  Choose the correct answer from the options given below :
One mole of an ideal gas at $300 \mathrm{~K}$ is expanded isothermally from $1 \mathrm{~L}$ to $10 \mathrm{~L}$ volume. $\Delta \mathrm{U}$ for this process is (Use $\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ )
What mass of $95%$ pure ${\mathrm{CaCO}}_{3}$ will be required to neutralise $50\mathrm{mL}$ of $0.5M\mathrm{HCl}$ solution according to the following reaction? ${\mathrm{CaCO}}_{3(s)}+2{\mathrm{HCl}}_{(\mathrm{aq})}\rightarrow {\mathrm{CaCl}}_{2(\mathrm{aq})}+{\mathrm{CO}}_{2(g)}+2{H}_{2}{O}_{(l)}$ [Calculate upto second place of decimal point]
The half life of a first order reaction is 2000 years. If the concentration after 8000 years is $0.02 \mathrm{M}$, then the initial concentration was :
When electromagnetic radiation of wavelength $300 \mathrm{~nm}$ falls on the surface of a metal, electrons are emitted with the kinetic energy of $1.68 \times 10^5$ $\mathrm{J} \mathrm{mol}^{-1}$. What is the minimum energy needed to remove an electron from the metal? $\begin{aligned} & \left(h=6.626 \times 10^{-34} \mathrm{Js}, \mathrm{c}=3 \times 10^8 \mathrm{~ms}^{-1},\right. \\ & \mathrm{N}_{\mathrm{A}}=6.022 \times 10^{23} \mathrm{~mol}^{-1} \end{aligned}$
$\mathrm{K}_{\mathrm{H}}$ value for some gases at the same temperature ' $\mathrm{T}$ ' are given: $\begin{array}{c|c} \text {gas } & \mathrm{K}_{\mathrm{H}} / \mathbf{k} \text { bar } \\ \hline \mathrm{Ar} & 40.3 \\ \mathrm{CO}_2 & 1.67 \\ \mathrm{HCHO} & 1.83 \times 10^{-5} \\ \mathrm{CH}_4 & 0.413 \end{array}$ where $\mathrm{K}_{\mathrm{H}}$ is Henry's Law constant in water. The order of their solubility in water is :
Given below are half cell reactions : ${\mathrm{MnO}}_{4}^{-}+8{H}^{+}+5{e}^{-}\rightarrow {\mathrm{Mn}}^{2+}+4{H}_{2}O$, ${E}_{{\mathrm{Mn}}^{2+}/{\mathrm{MnO}}_{4}^{-}}^{o}=-1.510V$ $\frac{1}{2}{O}_{2}+2{H}^{+}+2{e}^{-}\rightarrow {H}_{2}O$ ${E}_{{O}_{2}/{H}_{2}O}^{o}=+1.223V$ Will the permanganate ion, ${\mathrm{MnO}}_{4}^{-}$ liberate ${O}_{2}$ from water in the presence of an acid?
Identify the incorrect statement from the following.
Which of the following $p-V$ curve represents maximum work done?
The given graph is a representation of kinetics of a reaction.  The $y$ and $x$ axes for zero and first order reactions, respectively are
For a first order reaction $A\rightarrow$ Products, initial concentration of $A$ is $0.1M$, which becomes $0.001M$ after $5$ minutes. Rate constant for the reaction in ${\mathrm{min}}^{-1}$ is
If radius of second Bohr orbit of the ${\mathrm{He}}^{+}$ ion is $105.8\mathrm{pm}$, what is the radius of third Bohr orbit of ${\mathrm{Li}}^{2+}$ ion?
The rate of a first order reaction depends on
At $298K$, the standard electrode potentials of ${\mathrm{Cu}}^{2+}/\mathrm{Cu},{\mathrm{Zn}}^{2+}/\mathrm{Zn},{\mathrm{Fe}}^{2+}/\mathrm{Fe}$ and ${\mathrm{Ag}}^{+}/\mathrm{Ag}$ are $0.34V$, $-0.76V$, $-0.44V$ and $0.80V$, respectively. On the basis of standard electrode potential, predict which of the following reaction cannot occur?
Which of the following reactions is a decomposition redox reaction?
Standard electrode potential for the cell with cell reaction $\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(\mathrm{aq}) \longrightarrow \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$ is $1.1 \mathrm{~V}$. Calculate the standard gibbs energy change for the cell reaction. (Given $\mathrm{F}=96487 \mathrm{C} \mathrm{mol}^{-1}$ )
For a chemical reaction $4 \mathrm{~A}+3 \mathrm{~B} \rightarrow 6 \mathrm{C}+9 \mathrm{D}$ rate of formation of $\mathrm{C}$ is $6 \times 10^{-2} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$ and rate of disappearance of $\mathrm{A}$ is $4 \times 10^{-2} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$. The rate of reaction and amount of $B$ consumed in interval of 10 seconds, respectively will be:
$K_P$ for the following reaction is 3.0 at $1000 \mathrm{~K}$. $\mathrm{CO}_2(\mathrm{~g})+\mathrm{C}(\mathrm{s}) \rightleftharpoons 2 \mathrm{CO}(\mathrm{g})$ What will be the value of $\mathrm{K}_C$ for the reaction at the same temperature? (Given: $\mathrm{R}=0.083 \mathrm{~L} \mathrm{bar} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ )
In one molal solution that contains $0.5$ mole of a solute, there is
$0.01 \mathrm{M}$ acetic acid solution is $1 \%$ ionised, then $\mathrm{pH}$ of this acetic acid solution is :
The density of the solution is $2.15 \mathrm{~g} \mathrm{~mL}^{-1}$, then mass of $2.5 \mathrm{~mL}$ solution in correct significant figures is