Physical Chemistry PYQ — Page 7

How many grams of residue is obtained by heating $2.76$ g of silver carbonate? (Given: Molar mass of C, O and Ag are $12$, $16$ and $108$ g mol$^{-1}$ respectively)

Number of moles and number of molecules in $1.4187$ L of $SO_2$ at STP respectively are:

At the transition temperature $T$, $A \rightleftharpoons B$ and $\Delta G^0 = 105 - 35\log T$ where $A$ and $B$ are two states of substance $X$. The transition temperature in $°$C when pressure is $1$ atm is _______. (Nearest integer)

200 cc of $x \times 10^{-3} \mathrm{M}$ potassium dichromate is required to oxidise 750 cc of 0.6 M Mohr's salt solution in acidic medium. Here $x=$ $\_\_\_\_$.

For reaction $A \rightarrow P$, rate constant $k = 1.5 \times 10^3$ s$^{-1}$ at $27°$C. If activation energy for the above reaction is $60$ kJ mol$^{-1}$, then the temperature (in $°$C) at which rate constant, $k = 4.5 \times 10^3$ s$^{-1}$ is _______. (Nearest integer) Given : $\log 2 = 0.30$, $\log 3 = 0.48$, $R = 8.3$ J K$^{-1}$ mol$^{-1}$, $\ln 10 = 2.3$

The surface of sodium metal is irradiated with radiation of wavelength $x$ nm. The kinetic energy of ejected electrons is $2.8 \times 10^{-20}$ J. The work function of sodium is $2.3$ eV. The value of $x$ is _____ $\times 10^2$ nm. (Nearest integer) (Given: $h = 6.6 \times 10^{-34}$ J s; $1$ eV $= 1.6 \times 10^{-19}$ J; $c = 3.0 \times 10^8$ m s$^{-1}$)

$\mathrm{A} \rightarrow \mathrm{D}$ is an endothermic reaction occurring in three steps (elementary). (i) $\mathrm{A} \rightarrow \mathrm{B} \Delta \mathrm{H}_{i}=+\mathrm{ve}$ (ii) $\mathrm{B} \rightarrow \mathrm{C} \Delta \mathrm{H}_{i i}=-\mathrm{ve}$ (iii) $\mathrm{C} \rightarrow \mathrm{D} \Delta \mathrm{H}_{i i i}=-\mathrm{ve}$ Which of the following graphs between potential energy ($y$-axis) vs reaction coordinate (x -axis) correctly represents the reaction profile of $\mathrm{A} \rightarrow \mathrm{D}$ ?

Given, (A) $\mathrm{n}=5, \mathrm{~m}_{1}=-1$ (B) $\mathrm{n}=3, \mathrm{l}=2, \mathrm{~m}_{1}=-1, \mathrm{~m}_{\mathrm{s}}=+\frac{1}{2}$ The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are :

Arrange the following atomic orbitals of multi electron atoms in order of increasing energy. A. $n = 3, l = 2, m = +1$ B. $n = 4, l = 0, m = 0$ C. $n = 6, l = 1, m = 0$ D. $n = 5, l = 1, m = +1$ E. $n = 2, l = 1, m = +1$ Choose the correct answer from the options given below:

Given below are two statements: Statement I: For an ideal gas, heat capacity at constant volume is always greater than the heat capacity at constant pressure. Statement II: In a constant volume process, no work is produced and all the heat withdrawn goes into the chaotic motion and is reflected by a temperature increase of the ideal gas. In the light of the above statements, choose the correct answer from the options given below

Two positively charged particles $\mathrm{m}_{1}$ and $\mathrm{m}_{2}$ have been accelerated across the same potential difference of 200 keV as shown below.  [Given mass of $\mathrm{m}_{1}=1$ amu and $\mathrm{m}_{2}=4$ amu] The deBroglie wavelength of $\mathrm{m}_{1}$ will be $x$ times of $\mathrm{m}_{2}$. The value of $x$ is $\_\_\_\_$ (nearest integer)

What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

The work functions of two metals $\left(M_{A}\right.$ and $\left.M_{B}\right)$ are in the $1: 2$ ratio. When these metals are exposed to photons of energy 6 eV, the kinetic energy of liberated electrons of $M_{A}: M_{B}$ is in the ratio of $2.642: 1$. The work functions (in eV) of $M_{A}$ and $M_{B}$ are respectively.

The solubility product constants of $Ag_2CrO_4$ and $AgBr$ are $32x$ and $4y$ respectively at $298$ K. The value of $\left(\dfrac{\text{molarity of } Ag_2CrO_4}{\text{molarity of } AgBr}\right)$ can be expressed as :

$20\text{ g}$ hemoglobin in a $1\text{ L}$ aqueous solution (A) at $300\text{ K}$ is separated from pure water by semi permeable membrane. At equilibrium the height of solution in a tube dipped in a solution (A) is found to be $80.0\text{ mm}$ higher than the tube dipped in water. The molar mass of hemoglobin is _______ $\text{kg mol}^{-1}$. (Nearest integer) (Given : $g = 10\text{ m s}^{-2}$, $R = 8.3\text{ kPa dm}^3\text{ K}^{-1}\text{mol}^{-1}$, density of solution $= 1000\text{ kg m}^{-3}$)

Consider the following data. <table class="pyq-table"><tbody><tr><th>Electrolyte</th><th>$\Lambda^{\circ}_m$ (S cm$^2$ mol$^{-1}$)</th></tr><tr><td>$\text{BaCl}_2$</td><td>$x_1$</td></tr><tr><td>$\text{H}_2\text{SO}_4$</td><td>$x_2$</td></tr><tr><td>HCl</td><td>$x_3$</td></tr></tbody></table> $\text{BaSO}_4$ is sparingly soluble in water. If the conductivity of the saturated $\text{BaSO}_4$ solution is $x$ S cm$^{-1}$ then the solubility product of $\text{BaSO}_4$ can be given as (Here $\Lambda_m = \Lambda^{\circ}_m$)

$\mathrm{A} \rightarrow$ product (First order reaction). Three sets of experiment were performed for a reaction under similar experimental conditions: Run $1 \Rightarrow 100 \mathrm{~mL}$ of 10 M solution of reactant A Run $2 \Rightarrow 200 \mathrm{~mL}$ of 10 M solution of reactant A Run $3 \Rightarrow 100 \mathrm{~mL}$ of 10 M solution of reactant $\mathrm{A}+100 \mathrm{~mL}$ of $\mathrm{H}_{2} \mathrm{O}$ added. The correct variation of rate of reaction is

A substance ' X ' (1.5 g) dissolved in 150 g of a solvent ' Y ' (molar mass $=300 \mathrm{~g} \mathrm{~mol}^{-1}$) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent ' Y ' is $\_\_\_\_$ $\times 10^{-2}$. (nearest integer) [Given : $\mathrm{K}_{\mathrm{b}}$ of the solvent $=5.0 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$ ] Assume the solution to be dilute and no association or dissociation of $X$ takes place in solution.

The species having identical radii according to the Bohr's theory are: A. $H$ (first orbit) B. $He^+$ (first orbit) C. $He^+$ (Second orbit) D. $Li^{2+}$ (first orbit) E. $Be^{3+}$ (Second orbit) Choose the correct answer from the options given below:

  Which of the following point in Figure 2 most accurately represents the nodal surface as shown in Figure 1?

Given below are two statements: Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric analysis. Statement II: Phenolphthalein is a weak base, therefore it dissociates in acidic medium. In the light of the above statements, choose the correct answer from the options given below

Identify the INCORRECT statements from the following: A. Notation ${ }_{12}^{24} \mathrm{Mg}$ represents 24 protons and 12 neutrons. B. Wavelength of a radiation of frequency $4.5 \times 10^{15} \mathrm{~s}^{-1}$ is $6.7 \times 10^{-8} \mathrm{~m}$. C. One radiation has wavelength $=\lambda_{1}(900 \mathrm{~nm})$ and energy $=\mathrm{E}_{1}$. Other radiation has wavelength $=\lambda_{2}(300 \mathrm{~nm})$ and energy $=\mathrm{E}_{2}. \mathrm{E}_{1}: \mathrm{E}_{2}=3: 1$. D. Number of photons of light of wavelength 2000 pm that provides 1 J of energy is $1.006 \times 10^{16}$. Choose the correct answer from the options given below:

The plot of $\log _{10} \mathrm{~K}$ vs $\frac{1}{\mathrm{~T}}$ gives a straight line. The intercept and slope respectively are (where K is equilibrium constant).

$\mathrm{A} \longrightarrow \mathrm{B}$ (first reaction) $\mathrm{C} \longrightarrow \mathrm{D}$ (second reaction) Consider the above two first-order reactions. The rate constant for first reaction at 500 K is double of the same at 300 K. At $500 \mathrm{~K}, 50 \%$ of the reaction becomes complete in 2 hour. The activation energy of the second reaction is half of that of first reaction. If the rate constant at 500 K of the second reaction becomes double of the rate constant of first reaction at the same temperature; then rate constant for the second reaction at 300 K is $\_\_\_\_$ $\times 10^{-1}$ hour $^{-1}$ (nearest integer).