Physical Chemistry PYQ — Page 27

The number of given orbitals which have electron density along the axis is ${p}_{x},{p}_{y},{p}_{z},{d}_{\mathrm{xy}},{d}_{\mathrm{yz}},{d}_{\mathrm{xz}},{d}_{z}^{2},{d}_{{x}^{2}-{y}^{2}}$

On complete combustion, $0.492g$ of an organic compound gave $0.792g$ of ${\mathrm{CO}}_{2}$. The $%$ of carbon in the organic compound is (Nearest integer)

The total number of isoelectronic species from the given set is ________. ${O}^{2-},{F}^{–},\mathrm{Al},{\mathrm{Mg}}^{2+},{\mathrm{Na}}^{+},{O}^{+},\mathrm{Mg},{\mathrm{Al}}^{3+},F$

Consider the graph of Gibbs free energy G vs extent of reaction. The number of statement/s from the following which are true with respect to points (a), (b) and (c) is $______$  A. Reaction is spontaneous at (a) and (b) B. Reaction is at equilibrium at point (b) and non-spontaneous at point (c) C. Reaction is spontaneous at (a) and non-spontaneous at (c) D. Reaction is non-spontaneous at (a) and (b)

A and B are two substances undergoing radioactive decay in a container. The half life of A is $15\mathrm{min}$ and that of B is $5\mathrm{min}$. If the initial concentration of B is $4$ times that of A and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? ________min.

For certain chemical reaction $X\rightarrow Y$, the rate of formation of product is plotted against the time as shown in the figure. The number of Correct statement/s from the following is _____  (A) Over all order of this reaction is one (B) Order of this reaction can't be determined (C) In region-I and III, the reaction is of first and zero order respectively (D) In region-II, the reaction is of first order (E) In region-II, the order of reaction is in the range of $0.1$ to $0.9$.

$5g\mathrm{of}\mathrm{NaOH}$ was dissolved in deionized water to prepare a $450\mathrm{mL}$ stock solution. What volume (in mL) of this solution would be required to prepare $500\mathrm{mL}$ of $0.1M$ solution ? Given : Molar Mass of $\mathrm{Na},O\mathrm{and}H\mathrm{is}23,16\mathrm{and}1g{\mathrm{mol}}^{–1}$ respectively

A $300\mathrm{mL}$ bottle of soft drink has $0.2{\mathrm{MCO}}_{2}$ dissolved in it. Assuming ${\mathrm{CO}}_{2}$ behaves as an ideal gas, the volume of the dissolved ${\mathrm{CO}}_{2}$ at STP is _____ $\mathrm{mL}$. (Nearest integer) Given: At STP, molar volume of an ideal gas is $22.7L{\mathrm{mol}}^{-1}$

Millimoles of calcium hydroxyide required to produce $100\mathrm{mL}$ of the aqueous solution of $\mathrm{pH}12$ is $x\times {10}^{-1}$. The value of $x$ is _____ (Nearest integer). Assume complete dissociation.

Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R Assertion A : $5f$ electron can participate in bonding to a far greater extent than $4f$ electrons Reason R : $5f$ orbitals are not as buried as $4f$ orbitals In the light of the above statements, choose the correct answer from the options given below

The vapour pressure vs. temperature curve for a solution solvent system is shown below.  The boiling point of the solvent is _____°C.

The dissociation constant of acetic is $x\times {10}^{–5}$. When $25\mathrm{mL}\mathrm{of}0.2M{\mathrm{CH}}_{3}\mathrm{COONa}$ solution is mixed with $25\mathrm{mL}\mathrm{of}0.02M{\mathrm{CH}}_{3}\mathrm{COOH}$ solution, the $\mathrm{pH}$ of the resultant solution is found to be equal to $5$. The value of $x$ is _______.

The total change in the oxidation state of manganese involved in the reaction of ${\mathrm{KMnO}}_{4}$ and potassium iodide in the acidic medium is ________.

The number of molecules and moles in $2.8375$ litres of ${O}_{2}$ at $\mathrm{STP}$ are respectively

${\mathrm{KMnO}}_{4}$ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute ${H}_{2}{\mathrm{SO}}_{4}.$ Number of water molecules produced for $2$ molecules of ${\mathrm{KMnO}}_{4}$ is $_______$

The number of correct statement/s from the following is _____ . A.Larger the activation energy, smaller is the value of the rate constant. B. The higher is the activation energy, higher is the value of the temperature coefficient. C. At lower temperatures, increase in temperature causes more change in the value of $k$ than at higher temperature. D. A plot of $\mathrm{ln}k$ vs $\frac{1}{T}$ is a straight line with slope equal to $-\frac{\mathrm{Ea}}{R}$

The logarithm of equilibrium constant for the reaction ${\mathrm{Pd}}^{2+}+4{\mathrm{Cl}}^{-}\rightleftharpoons {\mathrm{PdCl}}_{4}^{2-}$ is (Nearest integer) Given: $\frac{2.303\mathrm{RT}}{F}=0.06V$ ${\mathrm{Pd}}_{(\mathrm{aq})}^{2+}+2{e}^{-}\rightleftharpoons \mathrm{Pd}(s){E}^{o}=0.83V$ ${\mathrm{PdCl}}_{4}^{2-}(\mathrm{aq})+2{e}^{-}\rightleftharpoons \mathrm{Pd}(s)+4{\mathrm{Cl}}^{-}(\mathrm{aq})$ ${E}^{o}=0.65V$

In an electrochemical reaction of lead, at standard temperature, if ${E}_{({\mathrm{Pb}}^{2+}/\mathrm{Pb})}^{o}=m\text{ Volt }$and ${E}_{({\mathrm{Pb}}^{4+}/\mathrm{Pb})}^{o}=n\mathrm{Volt},$then the value of $E^{\circ}({\mathrm{Pb}}^{2+}/{\mathrm{Pb}}^{4+})$ is given by $m–\mathrm{xn}$. The value of x is _______. (Nearest integer)

Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of hydrogen gas produced at STP from the reaction of $11.5g$ of zinc with excess $\mathrm{HCl}$ is $L$ (Nearest integer) (Given : Molar mass of $\mathrm{Zn}$ is $65.4g{\mathrm{mol}}^{-1}$ and Molar volume of ${H}_{2}$ at $\mathrm{STP}=22.7L$ )

The enthalpy change for the adsorption process and micelle formation respectively are

A metal chloride contains $55.0%$ of chlorine by weight. $100\mathrm{mL}$ vapours of the metal chloride at STP weigh $0.57g$. The molecular formula of the metal chloride is (Given: Atomic mass of chlorine is $35.5u$)

Electrons in a cathode ray tube have been emitted with a velocity of $1000{\mathrm{ms}}^{-1}$. The number of following statements which is/are true about the emitted radiation is Given : $h=6\times {10}^{-34}\mathrm{Js},{m}_{e}=9\times {10}^{-31}\mathrm{kg}$ (A ) The deBroglie wavelength of the electron emitted is $666.67\mathrm{nm}$ (B ) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube. (C) The cathode rays start from cathode and move towards anode. (D ) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube..

The rate constant for a first order reaction is $20{\mathrm{min}}^{-1}$. The time required for the initial concentration of the reactant to reduce to its $\frac{1}{32}$ level is $______\times {10}^{-2}\mathrm{min}$. (Nearest integer)

An organic compound gives $0.220g$ of ${\mathrm{CO}}_{2}$ and $0.126g$ of ${H}_{2}O$ on complete combustion. If the $%$ of carbon is $24$ then the $%$ of hydrogen is $_________\times {10}^{–1}.$ (Nearest integer)