Chapter 7

For the reaction \(\mathrm{Fe}_{2} \mathrm{~N}(\mathrm{~s})+\frac{3}{2} \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{Fe}(\mathrm{s})+\mathrm{NH}_{3}(\mathrm{~g})\) (a) \(K_{\mathrm{c}}=K_{\mathrm{p}}(\mathrm{RT})\) (b) \(K_{\mathrm{c}}=K_{\mathrm{p}}(\mathrm{RT})^{\frac{-1}{2}}\) (c) \(K_{\mathrm{c}}=K_{\mathrm{p}}(\mathrm{RT})^{\frac{1}{2}}\) (d) \(K_{\mathrm{c}}=K_{\mathrm{p}}(\mathrm{RT})^{\frac{3}{2}}\)

Arrange the following solutions in the decreasing order of \(\mathrm{pOH}\) : (A) \(0.01 \mathrm{M} \mathrm{HCl}\) (B) \(0.01 \mathrm{M} \mathrm{NaOH}\) (C) \(0.01 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONa}\) (D) \(0.01 \mathrm{M} \mathrm{NaCl}\) (a) \((\mathrm{A})>(\mathrm{C})>(\mathrm{D})>(\mathrm{B})\) (b) \((\mathrm{A})>(\mathrm{D})>(\mathrm{C})>(\mathrm{B})\) (c) \((\mathrm{B})>(\mathrm{C})>(\mathrm{D})>(\mathrm{A})\) (d) \((\mathrm{B})>(\mathrm{D})>(\mathrm{C})>(\mathrm{A})\)

The variation of equilibrium constant with temperature is given below: $$ \begin{array}{ll} {\text { Temperature }} & {\text { Equilibrium Constant }} \\ \mathrm{T}_{1}=25^{\circ} \mathrm{C} & \mathrm{K}_{1}=10 \\ \mathrm{~T}_{2}=100{ }^{\circ} \mathrm{C} & \mathrm{K}_{2}=100 \end{array} $$ The values of \(\Delta \mathrm{H}^{\circ}, \Delta \mathrm{G}^{\circ}\) at \(\mathrm{T}_{1}\) and \(\Delta \mathrm{G}^{\circ}\) at \(\mathrm{T}_{2}\) (in \(\mathrm{kj} \mathrm{mol}^{-1}\) ) respectively, are close to [use \(\left.\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]\) (a) \(28.4,-7.14\) and \(-5.71\) (b) \(0.64,-7.14\) and \(-5.71\) (c) \(28.4,-5.71\) and \(-14.29\) (d) \(0.64,-5.71\) and \(-14.29\)

An acidic buffer is obtained on mixing : (a) \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COOH}\) and \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{NaOH}\) (b) \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{HCl}\) and \(200 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{NaCl}\) (c) \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COOH}\) and \(200 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{NaOH}\) (d) \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{HCl}\) and \(200 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONa}\)

The value of \(\mathrm{Kc}\) is 64 at \(800 \mathrm{~K}\) for the reaction \(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{~g}) .\) The value of \(K_{\mathrm{c}}\) for the following reaction is : \(\mathrm{NH}_{3}(\mathrm{~g}) \rightleftharpoons \frac{1}{2} \mathrm{~N}_{2}(\mathrm{~g})+\frac{3}{2} \mathrm{H}_{2}(\mathrm{~g})\) (a) \(1 / 64\) (b) 8 (c) \(1 / 4\) (d) \(1 / 8\)

Consider the following reaction: \(\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g}) ; \mathrm{DH}^{0}=+58 \mathrm{~kJ}\) For each of the following cases ((i), (ii)), the direction in which the equilibrium shifts is : (i) Temperature is decreases (ii) Pressure is increased by adding \(\mathrm{N}_{2}\) at constant \(\mathrm{T}\). (a) (i) towards product, (ii) towards product (b) (i) towards reactant, (ii) towards product (c) (i) towards reactant, (ii) no change (d) (i) towards product, (ii) no change

The \(K_{\mathrm{sp}}\) for the following dissociation is \(1.6 \times 10^{-5}\) \(\mathrm{PbCl}_{2}(\mathrm{~s}) \rightleftharpoons \mathrm{Pb}^{2+}(a q)+2 \mathrm{Cl}^{-}(a q)\) Which of the following choices is correct for a mixture of \(300 \mathrm{~mL} 0.134 \mathrm{M}\) \(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}\) and \(100 \mathrm{~mL} 0.4 \mathrm{M} \mathrm{NaCl} ?\) (a) Not enough data provided (b) \(\mathrm{Q}K_{\mathrm{sp}}\) (d) \(\mathrm{Q}=K_{\mathrm{sp}}\)

The solubility product of \(\mathrm{Cr}(\mathrm{OH})_{3}\) at \(298 \mathrm{~K}\) is \(6.0 \times 10^{-31}\). The concentration of hydroxide ions in a saturated solution of \(\mathrm{Cr}(\mathrm{OH})_{3}\) will be: (a) \(\left(2.22 \times 10^{-31}\right)^{1 / 4}\) (b) \(\left(18 \times 10^{-31}\right)^{1 / 4}\) (c) \(\left(18 \times 10^{-31}\right)^{1 / 2}\) (d) \(\left(4.86 \times 10^{-29}\right)^{1 / 4}\)

If the equilibrium constant for \(\mathrm{A} \rightleftharpoons \mathrm{B}+\mathrm{C}\) is \(\mathrm{K}_{\mathrm{eq}}^{(1)}\) and that of \(\mathrm{B}+\mathrm{C} \rightleftharpoons \mathrm{P}\) is \(\mathrm{K}_{\mathrm{eq}}^{(2)}\), the equilibrium constant for \(\mathrm{A} \rightleftharpoons \mathrm{P}\) is : (a) \(\mathrm{K}_{\mathrm{eq}}^{(1)} / \mathrm{K}_{\mathrm{eq}}^{(2)}\) (b) \(\mathrm{K}_{\mathrm{eq}}^{(2)}-\mathrm{K}_{\mathrm{eq}}^{(1)}\) (c) \(\mathrm{K}_{\mathrm{eq}}^{(1)}+\mathrm{K}_{\mathrm{eq}}^{(2)}\) (d) \(\mathrm{K}_{\mathrm{eq}}^{(\mathrm{I})} \mathrm{K}_{\mathrm{eq}}^{(2)}\)

For the following Assertion and Reason, the correct option is: Assertion: The \(\mathrm{pH}\) of water increases with increase in temperature. Reason: The dissociation of water into \(\mathrm{H}^{+}\)and \(\mathrm{OH}^{-}\)is an exothermic reaction. (a) Both assertion and reason are true, and the reason is the correct explanation for the assertion. (b) Both assertion and reason are false. (c) Both assertion and reason are true, but the reason is not the correct explanation for the assertion. (d) Assertion is not true, but reason is true.

For the reaction, \(2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_{3}(\mathrm{~g})\) \(\mathrm{DH}=-57.2 \mathrm{~kJ} \mathrm{~mol}^{-1}\) and \(\mathrm{K}_{\mathrm{c}}=1.7 \times 10^{16}\) Which of the following statement is INCORRECT? [Main April 10, 2019 (II)] (a) The equilibrium constant is large suggestive of reaction going to completion and so no catalyst is required. (b) The equilibrium will shift in forward direction as the pressure increases. (c) The equilibrium constant decreases as the temperature increases. (d) The addition of inert gas at constant volume will not affect the equilibrium constant.

What is the molar solubility of \(\mathrm{Al}(\mathrm{OH})_{3}\) in \(0.2 \mathrm{M} \mathrm{NaOH}\) solution? Given that, solubility product of \(\mathrm{Al}(\mathrm{OH})_{3}=2.4 \times 10^{-24}\) : (a) \(3 \times 10^{-19}\) (b) \(12 \times 10^{-21}\) (c) \(3 \times 10^{-22}\) (d) \(12 \times 10^{-23}\)

In which one of the following equilibria, \(\mathrm{K}_{\mathrm{p}} \neq \mathrm{K}_{\mathrm{c}}\) ? (a) \(2 \mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{CO}(\mathrm{g})\) (b) \(2 \mathrm{HI}(\mathrm{g}) \rightleftharpoons \mathrm{H}_{2}(\mathrm{~g})+\mathrm{I}_{2}(\mathrm{~g})\) (c) \(\mathrm{NO}_{2}(\mathrm{~g})+\mathrm{SO}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{NO}(\mathrm{g})+\mathrm{SO}_{3}(\mathrm{~g})\) (d) \(2 \mathrm{NO}(\mathrm{g}) \rightleftharpoons \mathrm{N}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g})\)

The \(\mathrm{pH}\) of a \(0.02 \mathrm{M} \mathrm{NH}_{4} \mathrm{Cl}\) solution will be [given \(\mathrm{K}_{\mathrm{b}}\left(\mathrm{NH}_{4} \mathrm{OH}\right)=10^{-5}\) and \(\log 2=0.301]\) (a) \(2.65\) (b) \(4.35\) (c) \(4.65\) (d) \(5.35\)

Consider the following reversible chemical reactions: \(\mathrm{A}_{2}(\mathrm{~g})+\mathrm{B}_{2}(\mathrm{~g}) \rightleftharpoons{\mathrm{K}_{\mathrm{I}}}{\rightleftharpoons} 2 \mathrm{AB}(\mathrm{g}) \ldots \ldots(1)\) \(6 \mathrm{AB}(\mathrm{g}) \stackrel{\mathrm{K}_{2}}{\rightleftharpoons} 3 \mathrm{~A}_{2}(\mathrm{~g})+3 \mathrm{~B}_{2}(\mathrm{~g}) \ldots . .(2)\) The relation between \(\mathrm{K}_{1}\) and \(\mathrm{K}_{2}\) is: (a) \(\mathrm{K}_{1} \mathrm{~K}_{2}=\frac{1}{3}\) (b) \(\mathrm{K}_{2}=\mathrm{K}_{1}\) (c) \(\mathrm{K}_{2}=\mathrm{K}_{1}^{3}\) (d) \(\mathrm{K}_{1} \mathrm{~K}_{2}=3\)

If solubility product of \(\mathrm{Zr}_{3}\left(\mathrm{PO}_{4}\right)_{4}\) is denoted by \(\mathrm{K}_{s p}\) and its molar solubility is denoted by \(\mathrm{S}\), then which of the following relation between \(\mathrm{S}\) and \(\mathrm{K}\) is correct? (a) \(\mathrm{S}=\left(\frac{\mathrm{K}_{s p}}{144}\right)^{1 / 6}\) (b) \(\mathrm{S}=\left(\frac{\mathrm{K}_{s p}}{6912}\right)^{1 / 7}\) (c) \(\mathrm{S}=\left(\frac{\mathrm{K}_{s p}}{929}\right)^{1 / 9}\) (d) \(\mathrm{S}=\left(\frac{\mathrm{K}_{s p}}{216}\right)^{1 / 7}\)

In which of the following reactions, an increase in the volume of the container will favour the formation of products? (a) \(4 \mathrm{NH}_{3}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 4 \mathrm{NO}(\mathrm{g})+6 \mathrm{H}_{2} \mathrm{O}\) (l) (b) \(2 \mathrm{NO}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g})\) (c) \(3 \mathrm{O}_{2} \rightleftharpoons 2 \mathrm{O}_{3}(\mathrm{~g})\) (d) \(\mathrm{H}_{2}(\mathrm{~g})+\mathrm{I}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HI}(\mathrm{g})\)

Which of the following salts is the most basic in aqueous solution? (a) \(\mathrm{Al}(\mathrm{CN})_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{COOK}\) (c) \(\mathrm{FeCl}_{3}\) (d) \(\mathrm{Pb}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\)

The following reaction occurs in the Blast Furnace where iron ore is reduced to iron metal : \(\mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s})+3 \mathrm{CO}(\mathrm{g}) \rightleftharpoons 2 \mathrm{Fe}(1)+3 \mathrm{CO}_{2}(\mathrm{~g})\) Using the Le Chatelier's principle, predict which one of the following will not disturb the equilibrium? (a) Removal of CO (b) Removal of \(\mathrm{CO}_{2}\) (c) Addition of \(\mathrm{CO}_{2}\) (d) Addition of \(\mathrm{Fe}_{2} \mathrm{O}_{3}\)

An aqueous solution contains \(0.10 \mathrm{MH}_{2} \mathrm{~S}\) and \(0.20 \mathrm{M} \mathrm{HCl}\). If the equilibrium constants for the formation of \(\mathrm{HS}^{-}\)from \(\mathrm{H}_{2} \mathrm{~S}\) is \(1.0 \times 10^{-7}\) and that of \(\mathrm{S}^{2}\) from HS ions is \(1.2 \times 10^{-13}\) then the concentration of \(\mathrm{S}^{2-}\) ions in aqueous solution is : (a) \(5 \times 10^{-8}\) (b) \(3 \times 10^{-20}\) (c) \(6 \times 10^{-21}\) (d) \(5 \times 10^{-19}\)

The equilibrium constant at \(298 \mathrm{~K}\) for a reaction \(A+B \rightleftharpoons C+D\) is 100 . If the initial concentration of all the four species were \(1 \mathrm{M}\) each, then equilibrium concentration of \(D\) (in \(\mathrm{mol} \mathrm{L}^{-1}\) ) will be : (a) \(1.818\) (b) \(1.182\) (c) \(0.182\) (d) \(0.818\)

The minimum volume of water required to dissolve \(0.1 \mathrm{~g}\) lead (II) chloride to get a saturated solution \(\left(K_{\mathrm{Sp}}\right.\) of \(\mathrm{PbCl}_{2}=3.2 \times 10^{-8}\); atomic mass of \(\mathrm{Pb}=207 \mathrm{u}\) ) is : (a) \(1.798 \mathrm{~L}\) (b) \(0.36 \mathrm{~L}\) (c) \(17.95 \mathrm{~L}\) (d) \(0.18 \mathrm{~L}\)

\(\mathrm{p} K_{\mathrm{a}}\) of a weak acid (HA) and \(\mathrm{p} K_{\mathrm{b}}\) of a weak base \((\mathrm{BOH})\) are \(3.2\) and 3.4, respectively. The \(\mathrm{pH}\) of their salt (AB) solution is (a) \(7.2\) (b) \(6.9\) (c) \(7.0\) (d) \(1.0\)

The following reaction is performed at \(298 \mathrm{~K}\). [Main 2015] $$2 \mathrm{NO}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g})$$. The standard free energy of formation of \(\mathrm{NO}(\mathrm{g})\) is \(86.6 \mathrm{KJ} / \mathrm{mol}\) at \(298 \mathrm{~K}\). What is the standard free energy of formation of \(\mathrm{NO}_{2}(\mathrm{~g})\) at \(298 \mathrm{~K} ?\left(K_{\mathrm{p}}\right.\) \(\left.=1.6 \times 10^{12}\right)\). (a) \(86600-\frac{\ln \left(1.6 \times 10^{12}\right)}{\mathrm{R}(298)}\) (b) \(\quad 0.5\left[2 \times 86,600-R(298) \ln \left(1.6 \times 10^{12}\right)\right]\) (c) \(R(298) \ln \left(1.6 \times 10^{12}\right)-86600\) (d) \(86600+R(298) \ln \left(1.6 \times 10^{12}\right)\)

Addition of sodium hydroxide solution to a weak acid (HA) results in a buffer of \(\mathrm{pH} 6\). If ionisation constant of \(\mathrm{HA}\) is \(10^{-5}\), the ratio of salt to acid concentration in the buffer solution will be : (a) \(4: 5\) (b) \(1: 10\) (c) \(10: 1\) (d) \(5: 4\)

The increase of pressure on ice \(\rightleftharpoons\) water system at constant temperature will lead to (a) a decrease in the entropy of the system (b) an increase in the Gibb's energy of the system (c) no effect on the equilibrium (d) a shift of the equilibrium in the forward direction

The conjugate base of hydrazoic acid is: (a) \(\mathrm{N}^{-3}\) (b) \(\mathrm{N}_{3}^{-}\) (c) \(\mathrm{N}_{2}^{-}\) (d) \(\mathrm{HN}_{3}^{-}\)

For the reaction \(\mathrm{SO}_{2}(\mathrm{~g})+\frac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{SO}_{3}(\mathrm{~g})\), if \(K_{\mathrm{p}}=K_{\mathrm{c}}(R T)^{x}\). where the symbols have usual meaning then the value of \(x\) is (assuming ideality): (a) \(-1\) (b) \(-\frac{1}{2}\) (c) \(\frac{1}{2}\) (d) 1

In some solutions, the concentration of \(\mathrm{H}_{3} \mathrm{O}^{+}\)remains constant even when small amounts of strong acid or strong base are added to them. These solutions are known as: (a) Ideal solutions (b) Colloidal solutions (c) True solutions (d) Buffer solutions

What happens when an inert gas is added to an equilibrium keeping volume unchanged? [Main Online April 12, 2014] (a) More product will form (b) Less product will form (c) More reactant will form (d) Equilibrium will remain unchanged

How many litres of water must be added to 1 litre an aqueous solution of HCl with a pH of 1 to create an aqueous solution with \(\mathrm{pH}\) of 2 ? (a) \(0.1 \mathrm{~L}\) (b) \(0.9 \mathrm{~L}\) (c) \(2.0 \mathrm{~L}\) (d) \(9.0 \mathrm{~L}\)

In reaction \(\mathrm{A}+2 \mathrm{~B} \rightleftharpoons 2 \mathrm{C}+\mathrm{D}\), initial concentration of \(\mathrm{B}\) was \(1.5\) times of \([\mathrm{A}]\), but at equilibrium the concentrations of \(\mathrm{A}\) and \(\mathrm{B}\) became equal. The equilibrium constant for the reaction is: (a) 8 (b) 4 (c) 12 (d) 6

$$ \begin{aligned} &\mathrm{NaOH} \text { is a strong base. What will be } \mathrm{pH} \text { of } 5.0 \times 10^{-2} \mathrm{M} \mathrm{NaOH}\\\ &\text { solution ? }(\log 2=0.3) \end{aligned} $$ (a) \(14.00\) (b) \(13.70\) (c) \(13.00\) (d) \(12.70\)

Solubility product constant \(\left(K_{s p}\right)\) of salts of types \(M X, M X_{2}\) and \(M_{3} X\) at temperature \(T\) are \(4.0 \times 10^{-8}, 3.2 \times 10^{-14}\) and \(2.7 \times 10^{-15}\), respectively. Solubilities (mol \(\mathrm{dm}^{-3}\) ) of the salts at temperature ' \(T\) are in the order (a) \(M X>M X_{2}>M_{3} X\) (b) \(\mathrm{M}_{3} \mathrm{X}>\mathrm{MX}_{2}>\mathrm{MX}\) (c) \(M X_{2}>M_{3} X>M X\) (d) \(M X>M_{3} X>M X_{2}\)

\(2.5 \mathrm{~mL}\) of \((2 / 5) \mathrm{M}\) weak monoacidic base \(\left(K_{b}=1 \times 10^{-12}\right.\) at \(\left.25^{\circ}\right)\) is titrated \((2 / 15) \mathrm{M} \mathrm{HCl}\) in water at \(25^{\circ} \mathrm{C}\). The concentration of \(\mathrm{H}^{+}\)at equivalence point is \(\left(K_{w}=1 \times 10^{-14}\right.\) at \(\left.25^{\circ} \mathrm{C}\right)\) (a) \(3.7 \times 10^{-14} \mathrm{M}\) (b) \(3.2 \times 10^{-7} \mathrm{M}\) (c) \(\quad 3.2 \times 10^{-2} \mathrm{M}\) (d) \(2.7 \times 10^{-2} \mathrm{M}\)

The Haber's process for the formation of \(\mathrm{NH}_{3}\) at \(298 \mathrm{~K}\) is \(\mathrm{N}_{2}+3 \mathrm{H}_{2} \rightleftharpoons 2 \mathrm{NH}_{3} ; \Delta H=-46.0 \mathrm{~kJ} ;\) Which of the following is the correct statement (a) The condition for equilibrium is $$ G_{\mathrm{N}_{2}}+3 G_{\mathrm{H}_{2}}=2 G_{\mathrm{NH}_{3}} $$ where \(G\) is Gibb's free energy per mole of the gaseous species measured at that partial pressure. (b) On adding \(\mathrm{N}_{2}\), the equilibrium will shift to forward direction because according to \(\mathrm{II}^{\text {nd }}\) law of thermodynamics, the entropy must increase in the direction of spontaneous reaction (c) The catalyst will increase the rate of forward reaction by 2 times and that of backward reaction by \(1.5\) times (d) None of these

\(0.1\) mole of \(\mathrm{CH}_{3} \mathrm{NH}_{2}\left(K_{b}=5 \times 10^{-4}\right)\) is mixed with \(0.08\) mole of \(\mathrm{HCl}\) and diluted to one litre. What will be the \(\mathrm{H}^{+}\)concentration in the solution? (a) \(8 \times 10^{-2} \mathrm{M}\) (b) \(8 \times 10^{-11} \mathrm{M}\) (c) \(1.6 \times 10^{-11} \mathrm{M}\) (d) \(8 \times 10^{-5} \mathrm{M}\)

A \(0.004 \mathrm{M}\) solution of \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) is isotonic with \(0.010 \mathrm{M}\) solution of glucose at same temperature. The percentage dissociation of \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) is (a) \(25 \%\) (b) \(50 \%\) (c) \(75 \%\) (d) \(85 \%\)

Consider the following equilibrium in a closed container $$ \mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g}) $$ At a fixed temperature, the volume of the reaction container is halved. For this change, which of the following statements holds true regarding the equilibrium constant \(\left(K_{p}\right)\) and degree of dissociation \((\alpha)\) ? (a) neither \(K_{p}\) nor \(\alpha\) changes (b) both \(K_{p}\) and \(\alpha\) change (c) \(K_{p}\) changes, but \(\alpha\) does not change (d) \(K_{p}\) does not change, but \(\alpha\) changes

A weak acid \(\mathrm{H} X\) has the dissociation constant \(1 \times 10^{-5} \mathrm{M}\). It forms a salt \(\mathrm{Na} X\) on reaction with alkali. The percentage hydrolysis of \(0.1 \mathrm{M}\) solution of \(\mathrm{Na} X\) is (a) \(0.0001 \%\) (b) \(0.01 \%\) (c) \(0.1 \%\) (d) \(0.15 \%\)

The set with correct order of acidity is (a) \(\mathrm{HClO}<\mathrm{HClO}_{2}<\mathrm{HClO}_{3}<\mathrm{HClO}_{4}\) (b) \(\mathrm{HClO}_{4}<\mathrm{HClO}_{3}<\mathrm{HClO}_{2}<\mathrm{HClO}\) (c) \(\mathrm{HClO}<\mathrm{HClO}_{4}<\mathrm{HClO}_{3}<\mathrm{HClO}_{2}\) (d) \(\mathrm{HClO}_{4}<\mathrm{HClO}_{2}<\mathrm{HClO}_{3}<\mathrm{HClO}\)

For a sparingly soluble salt \(A_{p} B_{q}\), the relationship of its solubility product \(\left(L_{S}\right)\) with its solubility \((S)\) is [2001S] (a) \(L_{S}=S^{p+q} \cdot p^{p} \cdot q^{q}\) (b) \(L_{S}=S^{p+q} \cdot p^{q} \cdot q^{p}\) (c) \(L_{S}=S^{p q} \cdot p^{p} \cdot q^{q}\) (d) \(L_{S}=S^{p q} \cdot(p q)^{p+q}\)

The \(\mathrm{pH}\) of \(0.1 \mathrm{M}\) solution of the following salts increases in the order. (a) \(\mathrm{NaCl}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCN}<\mathrm{HCl}\) (b) \(\mathrm{HCl}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCl}<\mathrm{NaCN}\) (c) \(\mathrm{NaCN}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCl}<\mathrm{HCl}\) (d) \(\mathrm{HCl}<\mathrm{NaCl}<\mathrm{NaCN}<\mathrm{NH}_{4} \mathrm{Cl}\)

The following acids have been arranged in the order of decreasing acid strength. Identify the correct order. \(\mathrm{ClOH}\) (I), \(\mathrm{BrOH}(\mathrm{II}), \mathrm{IOH}(\mathrm{III})\) (a) \(\mathrm{I}>\mathrm{II}>\mathrm{III}\) (b) \(\mathrm{II}>\mathrm{I}>\mathrm{III}\) (c) \(\mathrm{III}>\mathrm{II}>\mathrm{I}\) (d) \(\mathrm{I}>\mathrm{III}>\mathrm{II}\)

For the reversible reaction, \(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{~g})\) at \(500^{\circ} \mathrm{C}\), the value of \(K_{p}\) is \(1.44 \times 10^{-5}\) when partial pressure is measured in atmospheres. The corresponding value of \(K_{c}\), with concentration in mole litre \(^{-1}\), is (a) \(\frac{1.44 \times 10^{-5}}{(0.082 \times 500)^{-2}}\) (b) \(\frac{1.44 \times 10^{-5}}{(8.314 \times 773)^{-2}}\) (c) \(\frac{1.44 \times 10^{-5}}{(0.082 \times 773)^{2}}\) (d) \(\frac{1.44 \times 10^{-5}}{(0.082 \times 773)^{-2}}\)

Which one is more acidic in aqueous solution. (a) \(\mathrm{NiCl}_{2}\) (b) \(\mathrm{FeCl}_{3}\) (c) \(\mathrm{AlCl}_{3}\) (d) \(\mathrm{BeCl}_{2}\)

The degree of dissociation of water at \(25^{\circ} \mathrm{C}\) is \(1.9 \times 10^{-7} \%\) and density is \(1.0 \mathrm{~g} \mathrm{~cm}^{-3} .\) The ionic constant for water is : (a) \(1.0 \times 10^{-10}\) (b) \(1.0 \times 10^{-14}\) (c) \(1.0 \times 10^{-16}\) (d) \(1.0 \times 10^{-8}\)

Amongst the following hydroxides, the one which has the lowest value of \(K_{s p}\) at ordinary temperature (about \(25^{\circ} \mathrm{C}\) ) is [1990-1 Mark] (a) \(\mathrm{Mg}(\mathrm{OH})_{2}\) (b) \(\mathrm{Ca}(\mathrm{OH})_{2}\) (c) \(\mathrm{Ba}(\mathrm{OH})_{2}\) (d) \(\mathrm{Be}(\mathrm{OH})_{2}\)

When equal volumes of the following solutions are mixed, precipitation of \(\mathrm{AgCl}\left(\mathrm{K}_{\mathrm{sp}}=1.8 \times 10^{-10}\right)\) will occur only with (a) \(10^{-4} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-4} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (b) \(10^{-5} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-5} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (c) \(10^{-6} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-6} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (d) \(10^{-10} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-10} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\)

Which of the following solutions will have \(\mathrm{pH}\) close to \(1.0 ?\) (a) \(100 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{HCl}+100 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{NaOH}\) (b) \(55 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{HCl}+45 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{NaOH}\) (c) \(10 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{HCl}+90 \mathrm{ml}\) of \((\mathrm{M} / 10) \mathrm{NaOH}\) (d) \(75 \mathrm{ml}\) of \((\mathrm{M} / 5) \mathrm{HCl}+25 \mathrm{ml}\) of \((\mathrm{M} / 5) \mathrm{NaOH}\)