Physical Chemistry PYQ — Page 3

Which of the following pairs of ions will have same spin only magnetic moment values within the pair? A. $\mathrm{Zn}^{2+}, \mathrm{Ti}^{2+}$ B. $\mathrm{Cr}^{2+}, \mathrm{Fe}^{2+}$ C. $\mathrm{Ti}^{3+}, \mathrm{Cu}^{2+}$ D. $\mathrm{V}^{2+}, \mathrm{Cu}^{+}$ Choose the correct answer from the options given below

Mass in grams of copper deposited by passing 9.6487 A current through a voltmeter containing copper sulphate solution for 100 seconds is (Given : Molar mass of $\mathrm{Cu}: 63 \mathrm{~g} \mathrm{~mol}^{-1}, 1 \mathrm{~F}=96487 \mathrm{C}$ )

At a given temperature and pressure, the equilibrium constant values for the equilibria are given below: $3 \mathrm{~A}_2+\mathrm{B}_2 \rightleftharpoons 2 \mathrm{~A}_3 \mathrm{~B}, \mathrm{~K}_1$ $\mathrm{A}_3 \mathrm{~B} \rightleftharpoons \frac{3}{2} \mathrm{~A}_2+\frac{1}{2} \mathrm{~B}_2, \mathrm{~K}_2$ The relation between $\mathrm{K}_1$ and $\mathrm{K}_2$ is :

A compound $X$ contains $32 \%$ of $A, 20 \%$ of $B$ and remaining percentage of $C$. Then, the empirical formula of X is : (Given atomic masses of $A=64 ; B=40 ; C=32 u$)

From the following select the one which is not an example of corrosion.

In which of the following equilibria, $\mathrm{K}_{\mathrm{p}}$ and $\mathrm{K}_{\mathrm{c}}$ are NOT equal?

The standard cell potential of the following cell $\mathrm{Zn}\left|\mathrm{Zn}^{2+}(\mathrm{aq})\right| \mathrm{Fe}^{2+}(\mathrm{aq}) \mid \mathrm{Fe}$ is 0.32 V . Calculate the standard Gibbs energy change for the reaction : $\mathrm{Zn}(\mathrm{s})+\mathrm{Fe}^{2+}(\mathrm{aq}) \rightarrow \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Fe}(\mathrm{s})$ (Given : $1 \mathrm{~F}=96487 \mathrm{C}$ )

The plot of osmotic pressure $(\Pi)$ vs concentration ( $\mathrm{mol} \mathrm{L}^{-1}$ ) for a solution gives a straight line with slope 25.73 $\mathrm{L}^{\text {bar mol-1}}$. The temperature at which the osmotic pressure measurement is done is

Mass of glucose $\left(\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6\right)$ required to be dissolved to prepare one litre of its solution which is isotonic with $15 \mathrm{~g} \mathrm{~L}^{-1}$ solution of urea $\left(\mathrm{NH}_3 \mathrm{CONH}_2\right)$ is (Given: Molar mass in $\mathrm{g} \mathrm{mol}{ }^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16, \mathrm{~N}: 14$ )

The work done during reversible isothermal expansion of one mole of hydrogen gas at $25^{\circ} \mathrm{C}$ from pressure of 20 atmosphere to 10 atmosphere is (Given $\mathrm{R}=2.0 \mathrm{cal} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ )

The equilibrium concentrations of the species in the reaction $A+B\rightleftharpoons C+D$ are $2,3,10\mathrm{and}6\mathrm{mol}{L}^{-1}$ respectively at $300K$. $\Delta {G}^{\circ }$ for the reaction is $(R=2\mathrm{cal}/\mathrm{mol}K)$

The conductivity of centimolar solution of $\mathrm{KCl}$ at $25^{\circ}C$ is $0.0210{\mathrm{ohm}}^{-1}{\mathrm{cm}}^{-1}$ and the resistance of the cell containing the solution at $25^{\circ}C$ is $60\mathrm{ohm}$. The value of cell constant is

Avogadros number is

Amongst the given options which of the following molecules/ion acts as a Lewis acid?

The correct option for the rate law that corresponds to overall first order reaction is

For a reaction $3 \mathrm{~A} \rightarrow 2 \mathrm{~B}$ The average rate of appearance of $B$ is given by $\frac{\Delta[B]}{\Delta t}$. The correct relation between the average rate of appearance of $B$ with the average rate of disappearance of $A$ is given in option

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R: Assertion A: Helium is used to dilute oxygen in diving apparatus. Reasons R: Helium has high solubility in ${O}_{2}$ In the light of the above statements, choose the correct answer from the options given below:

The right option for the mass of ${\mathrm{CO}}_{2}$ produced by heating $20g$ of $20%$ pure limestone is (Atomic mass of $\mathrm{Ca}=40$) $[{\mathrm{CaCO}}_{3}\overset{1200K}{\rightarrow }\mathrm{CaO}+{\mathrm{CO}}_{2}]$

The pH of a neutral solution at 25°C is

An acidic buffer is prepared by mixing:

Given below are two statements: one labelled as Assertion A and other is labelled as Reason R: Assertion A: A reaction can have zero activation energy Reason R: The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R: Assertion A: In equation ${\Delta }_{r}G=-{\mathrm{nFE}}_{\mathrm{cell}}$ value of ${\Delta }_{r}G$ depends on $n$. Reasons R: ${E}_{\mathrm{cell}}$ is an intensive property and ${\Delta }_{r}G$ is an extensive property. In the light of the above statements, choose the correct answer from the options given below:

The correct value of cell potential in volt for the reaction that occurs when the following two half cells are connected, is $\begin{aligned} & \mathrm{Fe}_{(\mathrm{aq})}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Fe}(\mathrm{s}), \mathrm{E}^{\circ}=-0.44 \mathrm{~V} \\ & \mathrm{Cr}_2 \mathrm{O}_7^{2-}(\mathrm{aq})+14 \mathrm{H}^{+}+6 \mathrm{e}^{-} \rightarrow 2 \mathrm{Cr}^{3+}+7 \mathrm{H}_2 \mathrm{O}, \mathrm{E}^0=+1.33 \mathrm{~V} \\ & \end{aligned}$

Select the correct statements from the following : A. Atoms of all elements are composed of two fundamental particles. B. The mass of the electron is $9.10939\times {10}^{-31}\mathrm{kg}$. C. All the isotopes of a given element show same chemical properties. D. Protons and electrons are collectively known as nucleons. E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter. Choose the correct answer from the options given below: