Physical Chemistry PYQ — Page 16

The ideal gas equation relating pressure P, volume V, number of moles n, and temperature T is:

Arrange the following solutions in order of their increasing boiling points. (i) $10^{-4} \mathrm{M~} \mathrm{NaCl}$ (ii) $10^{-4} \mathrm{M~}$ Urea (iii) $10^{-3} \mathrm{M~} \mathrm{NaCl}$ (iv) $10^{-2} \mathrm{M~} \mathrm{NaCl}$

Consider the following chemical equilibrium of the gas phase reaction at a constant temperature : $\mathrm{A}(\mathrm{~g}) \rightleftharpoons \mathrm{B}(\mathrm{~g})+\mathrm{C}(\mathrm{~g})$ If $p$ being the total pressure, $K_p$ is the pressure equilibrium constant and $\alpha$ is the degree of dissociation, then which of the following is true at equilibrium?

Consider an elementary reaction $\mathrm{A}(\mathrm{g})+\mathrm{B}(\mathrm{g}) \rightarrow \mathrm{C}(\mathrm{g})+\mathrm{D}(\mathrm{g})$ If the volume of reaction mixture is suddenly reduced to $\frac{1}{3}$ of its initial volume, the reaction rate will become ' $x$ ' times of the original reaction rate. The value of $x$ is :

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is ________ M. (Nearest Integer value) (Given : $\mathrm{Na}=23, \mathrm{I}=127, \mathrm{Ag}=108, \mathrm{~N}=14$, $\mathrm{O}=16 \mathrm{~g} \mathrm{~mol}^{-1}$)

For the thermal decomposition of $\mathrm{N}_2 \mathrm{O}_5(\mathrm{~g})$ at constant volume, the following table can be formed, for the reaction mentioned below. $2 \mathrm{~N}_2 \mathrm{O}_5(\mathrm{~g}) \rightarrow 2 \mathrm{~N}_2 \mathrm{O}_4(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g})$  $\mathrm{x}=\ldots \times 10^{-3} \mathrm{~atm} \text { [nearest integer] }$ Given : Rate constant for the reaction is $4.606 \times 10^{-2} \mathrm{~s}^{-1}$.

On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of \(\mathrm{CO}_2\) and 0.567 g of \(\mathrm{H}_2 \mathrm{O}\). The empirical formula mass of compound \((\mathrm{X})\) is ________ g. (Given molar mass in \(\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12, \mathrm{H}: 1, \mathrm{O}: 16\))

1.24 g of \(\mathrm{AX}_2\) (molar mass \(124 \mathrm{~g} \mathrm{~mol}^{-1}\) ) is dissolved in 1 kg of water to form a solution with boiling point of \(100.0156^{\circ} \mathrm{C}\), while \(25.4 \mathrm{~g}^{\circ}\) of \(\mathrm{AY}_2\) (molar mass \(250 \mathrm{~g} \mathrm{~mol}^{-1}\) ) in 2 kg of water constitutes a solution with a boiling point of \(100.0260^{\circ} \mathrm{C}\). \(\mathrm{K}_{\mathrm{b}}\left(\mathrm{H}_2 \mathrm{O}\right)=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\) Which of the following is correct ?

The metals that are employed in the battery industries are A. Fe, B. Mn, C. Ni, D. Cr, E. Cd Choose the correct answer from the options given below:

The following concentrations were observed at $500K$ for the formation of ${\mathrm{NH}}_{3}$ from ${N}_{2}$ and ${H}_{2}$. At equilibrium : $[{N}_{2}]=2\times {10}^{-2}M,[{H}_{2}]=3\times {10}^{-2}M$ and $[{\mathrm{NH}}_{3}]=1.5\times {10}^{-2}M$. Equilibrium constant for the reaction is ______.

Consider the following first order gas phase reaction at constant temperature \(\mathrm{A}(\mathrm{g}) \rightarrow 2 \mathrm{~B}(\mathrm{~g})+\mathrm{C}(\mathrm{g})\) If the total pressure of the gases is found to be 200 torr after \(23 \mathrm{sec}\). and 300 torr upon the complete decomposition of A after a very long time, then the rate constant of the given reaction is ______ \(\times 10^{-2} \mathrm{~s}^{-1}\) (nearest integer) [Given : \(\log _{10}(2)=0.301\)]

The potential for the given half cell at $298K$ is $(-)$............ $\times {10}^{-2}V.$ $2{H}_{(\mathrm{aq})}^{+}+2{e}^{-}\rightarrow {H}_{2}(g)$ $[{H}^{+}]=1M,{P}_{{H}_{2}}=2\mathrm{atm}$ (Given$2.303\mathrm{RT}/F=0.06V,\mathrm{log}2=0.3$)

Match List I with List II  Choose the correct answer from the options given below :-

For a strong electrolyte, a plot of molar conductivity against (concentration) \({ }^{1 / 2}\) is a straight line, with a negative slope, the correct unit for the slope is

A hypothetical electromagnetic wave is show below.  The frequency of the wave is \(x \times 10^{19} \mathrm{~Hz}\). \(x =\) ______ (nearest integer)

Solubility of calcium phosphate (molecular mass, $M$) in water is ${W}_{g}$ per $100\mathrm{mL}$ at $25^{\circ}C.$ Its solubility product at $25^{\circ}C$ will be approximately.

Identify the factor from the following that does not affect electrolytic conductance of a solution.

The equilibrium \(\mathrm{Cr}_2 \mathrm{O}_7^{2-} \rightleftharpoons 2 \mathrm{CrO}_4^{2-}\) is shifted to the right in :

The molar conductivity for electrolytes \(A\) and \(B\) are plotted against \(C^{1 / 2}\) as shown below. Electrolytes \(A\) and \(B\) respectively are : 

Identify the mixture that shows positive deviations from Raoult's Law

For a reaction \(\mathrm{A} \xrightarrow{\mathrm{K}_1} \mathrm{~B} \xrightarrow{\mathrm{K}_2} \mathrm{C}\) If the rate of formation of \(B\) is set to be zero then the concentration of \(B\) is given by :

Chlorine undergoes disproportionation in alkaline medium as shown below : ${\mathrm{aCl}}_{2}(g)+{\mathrm{bOH}}^{-}(\mathrm{aq})\rightarrow {\mathrm{cClO}}^{-}(\mathrm{aq})+{\mathrm{dCl}}^{-}(\mathrm{aq})+{\mathrm{eH}}_{2}O(l)$ The values of $a,b,c$ and $d$ in a balanced redox reaction are respectively :

Only \(2 \mathrm{~mL}\) of \(\mathrm{KMnO}_4\) solution of unknown molarity is required to reach the end point of a titration of \(20 \mathrm{~mL}\) of oxalic acid \((2 \mathrm{M})\) in acidic medium. The molarity of \(\mathrm{KMnO}_4\) solution should be \(\qquad\) M.

Which of the following cannot function as an oxidising agent?