Physical Chemistry PYQ — Page 18

A solution of two miscible liquids showing negative deviation from Raoult's law will have :

$1$ mole of $\mathrm{PbS}$ is oxidised by $X$ moles of ${O}_{3}$ to get $Y$ moles of ${O}_{2}.$ $X+Y=$

The quantity of silver deposited when one coulomb charge is passed through \(\mathrm{AgNO}_3\) solution :

Consider the following reactions \(\mathrm{NiS}+\mathrm{HNO}_3+\mathrm{HCl} \rightarrow \mathrm{A}+\mathrm{NO}+\mathrm{S}+\mathrm{H}_2 \mathrm{O}\) \(\begin{aligned} \mathrm{A}+\mathrm{NH}_4 \mathrm{OH}+\mathrm{H}_3 \mathrm{C}-\mathrm{C} & =\mathrm{N}-\mathrm{OH} \\ | ~\\ \mathrm{H}_3 \mathrm{C}-\mathrm{C} & =\mathrm{N}-\mathrm{OH}\end{aligned} \rightarrow \mathrm{B}+\mathrm{NH}_4 \mathrm{Cl}+\mathrm{H}_2 \mathrm{O}\) The number of protons that do not involve in hydrogen bonding in the product \(B\) is ______.

Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following :

A solution containing \(10 \mathrm{~g}\) of an electrolyte \(\mathrm{AB}_2\) in \(100 \mathrm{~g}\) of water boils at \(100.52^{\circ} \mathrm{C}\). The degree of ionization of the electrolyte \((\alpha)\) is _______ \(\times 10^{-1}\). (nearest integer) [Given : Molar mass of \(\mathrm{AB}_2=200 \mathrm{~g} \mathrm{~mol}^{-1}, \mathrm{~K}_{\mathrm{b}}\) (molal boiling point elevation const. of water) \(=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\), boiling point of water \(=100^{\circ} \mathrm{C} ; \mathrm{AB}_2\) ionises as \(\left.\mathrm{AB}_2 \rightarrow \mathrm{A}^{2+}+2 \mathrm{~B}^{-}\right]\)

Thiosulphate reacts differently with iodine and bromine in the reactions given below: \(\begin{aligned} & 2 \mathrm{~S}_2 \mathrm{O}_3^{2-}+\mathrm{I}_2 \rightarrow \mathrm{S}_4 \mathrm{O}_6^{2-}+2 \mathrm{I}^{-} \\ & \mathrm{S}_2 \mathrm{O}_3^{2-}+5 \mathrm{Br}_2+5 \mathrm{H}_2 \mathrm{O} \rightarrow 2 \mathrm{SO}_4^{2-}+4 \mathrm{Br}^{-}+10 \mathrm{H}^{+} \end{aligned}\) Which of the following statement justifies the above dual behaviour of thiosulphate?

The rate of first order reaction is $0.04\mathrm{mol}{L}^{-1}{s}^{-1}$ at $10$ minutes and $0.03\mathrm{mol}{L}^{-1}{s}^{-1}$ at $20$ minutes after initiation. Half life of the reaction is ______ minutes. (Given $\mathrm{log}2=0.3010,\mathrm{log}3=0.4771)$ Round off your answer to the nearest integer.

Which of the following statements is not correct about rusting of iron?

Molar ionic conductivities of divalent cation and anion are \(57 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}\) and \(73 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}\) respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be :

What pressure (bar) of \(\mathrm{H}_2\) would be required to make emf of hydrogen electrode zero in pure water at \(25^{\circ} \mathrm{C}\) ?

According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship between wavelength of electron $(\lambda )$ and momentum of electron $(p)?$

The Molarity \((\mathrm{M})\) of an aqueous solution containing \(5.85 \mathrm{~g}\) of NaCl in \(500 \mathrm{~mL}\) water is : (Given : Molar Mass \(\mathrm{Na}: 23\) and \(\mathrm{Cl}: 35.5 \mathrm{gmol}^{-1}\) )

Total number of ions from the following with noble gas configuration is ${\mathrm{Sr}}^{2+}(Z=38),{\mathrm{Cs}}^{+}(Z=55),{\mathrm{La}}^{2+}(Z=57){\mathrm{Pb}}^{2+}$$(Z=82),{\mathrm{Yb}}^{2+}(Z=70)\text{ and }{\mathrm{Fe}}^{2+}(Z=26)$

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will - 

Molality ( \(\mathrm{m}\) ) of \(3 \mathrm{M}\) aqueous solution of \(\mathrm{NaCl}\) is : (Given : Density of solution \(=1.25 \mathrm{~g} \mathrm{~mL}^{-1}\), Molar mass in \(\mathrm{g} \mathrm{mol}^{-1}: \mathrm{Na}-23, \mathrm{Cl}-35.5\))

Match List I with List II \(\begin{array}{|l|l|l|l|} \hline & \text{ List - I (Cell) } & & \text{List - II (Use/Property/Reaction)} \\ \hline \text { A. } & \text { Leclanche cell } & \text { I. } & \begin{array}{l} \text { Converts energy of combustion into electrical } \\ \text { energy } \end{array} \\ \hline \text { B. } & \mathrm{Ni}-\mathrm{Cd} \text { cell } & \text { II. } & \begin{array}{l} \text { Does not involve any ion in solution and is used } \\ \text { in hearing aids } \end{array} \\ \hline \text { C. } & \text { Fuel cell } & \text { III. } & \text { Rechargeable } \\ \hline \text { D. } & \text { Mercury cell } & \text { IV. } & \text { Reaction at anode } \mathrm{Zn} \rightarrow \mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \\ \hline \end{array}\) Choose the correct answer from the options given below:

The ionization energy of sodium in $\mathrm{kJ}{\mathrm{mol}}^{–1}$ . If electromagnetic radiation of wavelength $242\mathrm{nm}$ is just sufficient to ionize sodium atom is ______.(nearest integer)

Consider the two different first order reactions given below \(\mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}\) (Reaction 1\()\) \(P \rightarrow Q\) (Reaction 2) The ratio of the half life of Reaction 1 : Reaction 2 is \(5: 2\). If \(t_1\) and \(t_2\) represent the time taken to complete \(2 / 3^{\text {rd }}\) and \(45^{\text {th }}\) of Reaction 1 and Reaction 2, respectively, then the value of the ratio \(t_1: t_2\) is ______ \(\times 10^{-1}\) (nearest integer). [Given : \(\log _{10}(3)=0.477\) and \(\log _{10}(5)=0.699\)]

The heat of solution of anhydrous \(\mathrm{CuSO}_4\) and \(\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}\) are \(-70 \mathrm{~kJ} \mathrm{~mol}^{-1}\) and \(+12 \mathrm{~kJ} \mathrm{~mol}^{-1}\) respectively. The heat of hydration of \(\mathrm{CuSO}_4\) to \(\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}\) is \(-x \mathrm{~kJ}\). The value of \(x\) is ______ (nearest integer).

An ideal gas, \(\overline{\mathrm{C}}_{\mathrm{v}}=\frac{5}{2} \mathrm{R}\), is expanded adiabatically against a constant pressure of 1 atm untill it doubles in volume. If the initial temperature and pressure is \(298 \mathrm{~K}\) and \(5 \mathrm{~atm}\), respectively then the final temperature is _______ \(\mathrm{K}\) (nearest integer). [\(\overline{\mathrm{C}}_{\mathrm{v}}\) is the molar heat capacity at constant volume]

If $5$ moles of an ideal gas expands from $10L$ to a volume of $100L$ at $300K$ under isothermal and reversible condition then work, $w$, is $-xJ$. The value of $x$ is $-$_______. (Given $R=8.314J{K}^{-1}{\mathrm{mol}}^{-1}$)

The enthalpy of formation of ethane \(\left(\mathrm{C}_2 \mathrm{H}_6\right)\) from ethylene by addition of hydrogen where the bond-energies of \(\mathrm{C}-\mathrm{H}, \mathrm{C}-\mathrm{C}, \mathrm{C}=\mathrm{C}, \mathrm{H}-\mathrm{H}\) are \(414 \mathrm{~kJ}, 347 \mathrm{~kJ}, 615 \mathrm{~kJ}\) and \(435 \mathrm{~kJ}\) respectively is \(\qquad\) \(\mathrm{kJ}\)

Given below are two statements : Statement I : On passing \(\mathrm{HCl}_{(\mathrm{g})}\) through a saturated solution of \(\mathrm{BaCl}_2\), at room temperature white turbidity appears. Statement II : When \(\mathrm{HCl}\) gas is passed through a saturated solution of \(\mathrm{NaCl}\), sodium chloride is precipitated due to common ion effect. In the light of the above statements, choose the most appropriate answer from the options given below :