Chapter 8

The percentage hydrolysis of \(\mathrm{NaCN}\) in \(\left(\frac{\mathrm{N}}{80}\right)\) aqueous solution [Dissociation constant of \(\mathrm{HCN}\) is \(1.3 \times 10^{-9}\) and \(\left.\mathrm{K}_{\mathrm{w}}=1.0 \times 10^{-14}\right]\) is (a) \(8.2\) (b) \(9.6\) (c) \(5.26\) (d) \(2.48\)

Hydrolysis constant \(\mathrm{K}_{\mathrm{A}}\) and \(\mathrm{K}_{\mathrm{B}}\) of two salts of weak acids HA and \(\mathrm{HB}\) are \(10^{-8}\) and \(10^{-6}\) respectively. If the dissociation constant of third acid \(\mathrm{HC}\) is \(10^{-2}\). The order of acidic strengths of three acids will be (a) \(\mathrm{HA}>\mathrm{HB}>\mathrm{HC}\) (b) \(\mathrm{HB}>\mathrm{HA}>\mathrm{HC}\) (c) \(\mathrm{HC}>\mathrm{HA}>\mathrm{HB}\) (d) \(\mathrm{HA}=\mathrm{HB}=\mathrm{HC}\)

A solution containing \(\mathrm{NH}_{4} \mathrm{Cl}\) and \(\mathrm{NH}_{4} \mathrm{OH}\) has a hydroxide ion concentration of \(10^{-6}\) mol litre \(^{-1}\), which of the following hydroxides could be precipitated when this solution is added in equal volume to a solution containing \(0.1 \mathrm{M}\) of metal ions? (a) \(\mathrm{AgOH}\left(\mathrm{K}_{\mathrm{sp}}=5 \times 10^{-3}\right)\) (b) \(\mathrm{Cd}(\mathrm{OH})_{2}\left(\mathrm{~K}_{s \mathrm{p}}=8 \times 10^{-6}\right)\) (c) \(\mathrm{Mg}(\mathrm{OH})_{2}\left(\mathrm{~K}_{\mathrm{sp}}=3 \times 10^{-11}\right)\) (d) \(\mathrm{Fe}(\mathrm{OH})_{3}\left(\mathrm{~K}_{3 \mathrm{sp}}=8 \times 10^{-16}\right)\)

In the precipitation titration of \(\mathrm{KCl}\) against \(\mathrm{AgNO}_{3}\), \(\mathrm{K}_{2} \mathrm{CrO}_{4}\) is used as an indicator since, \(\mathrm{AgCl}\) is white coloured. End point is detected by appearance of deep yellow coloured precipitate of \(\mathrm{Ag}_{2} \mathrm{CrO}_{4}\). The minimum concentration of chromate ion required for detectionof end point is \(\left[\mathrm{K}_{s p}\right.\) of \(\mathrm{AgCl}=2.5 \times 10^{-10}\) and \(\mathrm{K}_{\text {sp }}\) of \(\left.\mathrm{Ag}_{2} \mathrm{CrO}_{4}=1.8 \times 10^{-12}\right]\) (a) \(7.3 \times 10^{-2} \mathrm{M}\) (b) \(5.3 \times 10^{-4} \mathrm{M}\) (c) \(7.3 \times 10^{-3} \mathrm{M}\) (d) \(3.6 \times 10^{-5} \mathrm{M}\)

The concentration of hydroxyl ion in a solution left after mixing \(100 \mathrm{~mL}\) of \(0.1 \mathrm{M} \mathrm{MgCl}_{2}\) and \(100 \mathrm{~mL}\) of \(0.2 \mathrm{M} \mathrm{NaOH}\left[\mathrm{K}_{\mathrm{sp}}\right.\) of \(\left.\mathrm{Mg}(\mathrm{OH})_{2}=1.2 \times 10^{-11}\right]\) is (a) \(2.8 \times 10^{-3}\) (b) \(2.8 \times 10^{-2}\) (c) \(2.8 \times 10^{-4}\) (d) \(2.8 \times 10^{-5}\)

When \(0.1\) mol of \(\mathrm{CH}_{3} \mathrm{NH}_{2}\left(\mathrm{~K}_{b}=5 \times 10^{-4}\right)\) is mixedwith \(0.08\) mol of \(\mathrm{HCl}\) and diluted to \(1 \mathrm{~L}\), the \(\mathrm{H}^{+}\)ion concentration in the solution is (a) \(8 \times 10^{-11} \mathrm{M}\) (b) \(6 \times 10^{-5} \mathrm{M}\) (c) \(1.6 \times 10^{-11} \mathrm{M}\) (d) \(8 \times 10^{-2} \mathrm{M}\)

When \(\mathrm{H}_{2} \mathrm{~S}\) is passed through an aqueous solution of an equilimolar mixture of \(\mathrm{Zn}^{2+}\) and \(\mathrm{Pb}^{2+}\) acidified with dilute acetic acid, \(\mathrm{ZnS}\) is not precipitated, because (a) \(\mathrm{K}_{\mathrm{sp}}(\mathrm{ZnS})<\mathrm{K}_{\mathrm{sp}}(\mathrm{PbS})\) (b) \(\mathrm{K}_{\mathrm{sp}}(\mathrm{ZnS})>\mathrm{K}_{\mathrm{sp}}^{\mathrm{sp}}(\mathrm{PbS})\) (c) \(\mathrm{H}_{2} \mathrm{~S}\) decreases the \(\mathrm{K}_{\mathrm{sp}}\) of \(\mathrm{ZnS}\) (d) \(\mathrm{H}_{2} \mathrm{~S}\) increases the \(\mathrm{K}_{\mathrm{sp}}\) of \(\mathrm{PbS}\)

When equal volumes of the following solutions are mixed, the precipitation of \(\mathrm{AgCl}\left(\mathrm{K}_{\mathrm{sp}}=1.8 \times 10^{-10}\right)\) will occur with (a) \(10^{-5} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-3} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (b) \(10^{-4} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-4} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (c) \(10^{-5} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-1} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\) (d) \(10^{-5} \mathrm{M}\left(\mathrm{Ag}^{+}\right)\)and \(10^{-5} \mathrm{M}\left(\mathrm{Cl}^{-}\right)\)

Mark the correct statements (a) \(\mathrm{pK}_{\mathrm{a}}+\mathrm{pK}_{\mathrm{b}}=\mathrm{pK}_{\mathrm{w}}\), at all temperatures. (b) Acetic acid behaves like a strong acid in \(\mathrm{NH}_{3}\). (c) \(\mathrm{H}_{3} \mathrm{O}^{+}\)is a strong nucleophile (d) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{O}^{-}\)is a weaker base than \(\mathrm{OH}^{-}\).

Which of the following statements is/are correct about the ionic product of water ? (a) At \(25^{\circ} \mathrm{C}, \mathrm{K}\) (dissociation constant of water \()>\mathrm{K}_{w}\) (ionic product of water) (b) \(\mathrm{K}_{\mathrm{w}}\) of boiling water is greater than \(10^{-14}\). (c) Ionic product of water at \(25^{\circ} \mathrm{C}\) is \(10^{-14}\) (d) \(\mathrm{pH}+\mathrm{pOH}=\mathrm{pK}_{\mathrm{w}}\).

If molar concentrations of two weak acids are the same, their relative strengths can be compared by (a) \(\frac{\alpha_{1}}{\alpha_{2}}\) (b) \(\frac{\mathrm{K}_{1}}{\mathrm{~K}_{2}}\) (c) \(\sqrt{\mathrm{K}_{1} / \mathrm{K}_{2}}\) (d) \(\frac{\left[\mathrm{H}^{+}\right]_{1}}{\left[\mathrm{H}^{+}\right]_{2}}\)

Which of the following are the correct statements (a) The \(\mathrm{pH}\) of blood is same in summer and winter (b) \(\mathrm{pH}\) of an acidic buffer increases if more salt is added (c) \(\mathrm{pH}\) of a basic buffer decreases if more salt is added (d) The term solubility product is only for sparingly soluble salts

Which of the following statements are correct? (a) The conjugate base of \(\mathrm{H}_{2} \mathrm{PO}_{4}^{-}\)is \(\mathrm{HPO}_{4}^{2-}\). (b) \(\mathrm{pH}\) of \(1.0 \times 10^{-8} \mathrm{M}\) aqueous solution of \(\mathrm{HCl}\) is 8 . (c) When a weak monoprotic acid solution is treated with a strong base, at half neutralization point, \(\mathrm{pH}=\frac{1}{2} \mathrm{pK}_{\mathrm{a}}\) (d) The autoprotolysis constant of water increases with temperature.

Which of the following solutions will have no effect on pH on dilution? (a) \(0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONa}\) (b) \(1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONH}_{4}\) (c) \(0.1 \mathrm{M} \mathrm{NH}_{4} \mathrm{OH}+0.1 \mathrm{M} \mathrm{NH}_{4} \mathrm{Cl}\) (d) \(0.5 \mathrm{M} \mathrm{H}_{2} \mathrm{CO}_{3}+0.5 \mathrm{M} \mathrm{NaHCO}_{3}\)

For the reaction \(\mathrm{AB}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{A}(\mathrm{g})+\mathrm{B}_{2}(\mathrm{~g})\) The degree of dissociation ' \(\alpha\) ' is negligible as compared to 1 (unity); the degree of dissociation may be expressed as: (a) \(\alpha \propto \frac{1}{\sqrt{\mathrm{P}}}\) (b) \(\alpha \propto \sqrt{\mathrm{V}}\) (c) \(\alpha \propto \frac{1}{P}\) (d) \(\alpha \propto \frac{1}{\mathrm{~V}}\)

A buffer solution can be prepared from a mixture of (a) \(\mathrm{CH}_{3} \mathrm{COONa}\) and \(\mathrm{CH}_{3} \mathrm{COOH}\) in water (b) \(\mathrm{CH}_{3} \mathrm{COONa}\) and \(\mathrm{HCl}\) in water under certain conditions (c) \(\mathrm{NH}_{4} \mathrm{OH}\) and \(\mathrm{NH}_{4} \mathrm{Cl}\) in water (d) \(\mathrm{NaCl}\) and \(\mathrm{HCl}\) in water

Which of the following solution in water act as buffer? (a) \(0.5\) mol of pyridine \(+0.5\) mol of Pyridinium chloride(b) \(0.1 \mathrm{~mol}\) of \(\mathrm{NaOH}+0.15 \mathrm{~mol}\) of \(\mathrm{CH}_{3} \mathrm{COOH}\) (c) \(\mathrm{CH}_{3} \mathrm{COONH}_{4}\) (d) \(0.25 \mathrm{~mol}\) of \(\mathrm{NH}_{4} \mathrm{Cl}+0.5 \mathrm{~mol}\) of \(\mathrm{NaOH}\).

The concentration of acetic acid, which can be added to \(\mathrm{N} / 2\) formic acid so that the percentage dissociation of both acids is unchanged, would be \(\left(\mathrm{K}_{\mathrm{a}}\right.\) of \(\mathrm{HCO}_{2} \mathrm{H}\) and \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\) are \(2.4 \times 10^{-4} \mathrm{M}\) and \(1.8 \times 10^{-5} \mathrm{M}\) respectively) (a) \(20 \mathrm{~N} / 2\) (b) \(\mathrm{N} / 2\) (c) N/4 (d) \(10 \mathrm{~N} / 3\)

Equal volumes of \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\) (c M) solution of \(\mathrm{pH}=5\) is mixed with HCl solution of same \(\mathrm{pH}\). Which of the following is an incorrect statement? (a) Concentration of \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\) will become \(\mathrm{c} / 2 \mathrm{M}\) after mixing \(\mathrm{HCl}\) with it. (b) Concentration of \(\mathrm{H}^{+}\)after mixing the two solutions is \(10^{-5} \mathrm{M}\). (c) The degree of dissociation of \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\) is suppressed due to addition of \(\mathrm{HCl}\). (d) Original concentration of \(\mathrm{HCl}\) was \(10^{-5} \mathrm{M}\). Passage-2 Solubility product of an electrolyte at a particular temperature is defined as the product of conc. of its ions in a saturated solution, each conc. raised to the power equal to the number of ions produced on dissociation of one molecule of the electrolyte. \(\mathrm{A}_{\mathrm{x}} \mathrm{B}_{\mathrm{y}} \rightleftharpoons \mathrm{xA}^{+}+\mathrm{yB}^{-}\) \(\mathrm{K}_{\mathrm{sp}}=\left[\mathrm{A}^{+}\right]^{\mathrm{x}}\left[\mathrm{B}^{-}\right]^{\mathrm{y}}\) Ionic product of the electrolyte \(\mathrm{A}_{x} \mathrm{~B}_{y}\) is also equal to \(\left[\mathrm{A}^{+}\right]^{\times}\left[\mathrm{B}^{-}\right]^{\mathrm{y}}\) but it is applicable to all types of solutions, which may be saturated or unsaturated.

The solubility product of \(\mathrm{AgCl}\) is \(1.8 \times 10^{-10}\) at \(298 \mathrm{~K}\). The solubility of \(\mathrm{AgCl}\) in \(0.01 \mathrm{M} \mathrm{HCl}\) solution is (a) \(1.8 \times 10^{-8} \mathrm{M}\) (b) \(1.4 \times 10^{-6} \mathrm{M}\) (c) \(1.8 \times 10^{-6} \mathrm{M}\) (d) \(1.4 \times 10^{-4} \mathrm{M}\)

Three sparingly soluble salts \(\mathrm{M}_{2} \mathrm{~B}, \mathrm{MB}\) and \(\mathrm{MB}_{3}\) have the same solubility product. Their solubilities will be in the order (a) \(\mathrm{MB}_{3}>\mathrm{M}_{2} \mathrm{~B}>\mathrm{MB}\) (b) \(\mathrm{MB}>\mathrm{M}_{2} \mathrm{~B}>\mathrm{MB}_{3}\) (c) \(\mathrm{MB}_{3}>\mathrm{MB}>\mathrm{M}_{2} \mathrm{~B}\) (d) \(\mathrm{MB}>\mathrm{MB}_{3}>\mathrm{M}_{2}^{2} \mathrm{~B}\)

\(50 \mathrm{~mL}\) of \(0.1 \mathrm{M}\) aqueous acetic acid is titrated with \(10 \mathrm{~mL}\) of \(0.1 \mathrm{M}\) aqueous \(\mathrm{NaOH}\) solution. The \(\mathrm{pH}\) of resulting solution is \(\left(\mathrm{pK}_{\mathrm{a}}\right.\) of acetic acid is \(4.7, \log 2=\) \(0.3010\) ) (a) \(5.098\) (b) \(5.030\) (c) \(4.098\) (d) \(5.3020\)

\(50 \mathrm{~mL}\) of \(0.2 \mathrm{M}\) aqueous \(\mathrm{CH}_{3} \mathrm{COOH}\) is mixed with \(50 \mathrm{~mL}\) of \(0.2 \mathrm{M}\) aqueous \(\mathrm{KOH}\) solution. The \(\mathrm{pH}\) of resulting solution is \(\left(\mathrm{pK}_{\mathrm{a}}\right.\) of acetic acid is \(4.7\) ) (a) \(7.0\) (b) \(9.35\) (c) \(8.85\) (d) \(6.05\)

$$ \begin{aligned} &\text { Match the following }\\\ &\begin{array}{ll} \hline \text { Column-I } & \text { Column-II } \\ \hline \text { (a) } \mathrm{FeCl}_{3} \text { solution (aqueous) } & \text { (p) } \mathrm{pH}<7 \\ \text { (b) } \mathrm{CH}_{3} \text { COONa solution (aqueous) } & \text { (q) } \mathrm{pH}>7 \\ \text { (c) Mixture of } 0.1 \mathrm{M} \text { acetic acid and } & \text { (r) } \mathrm{pH}=7 \\ 0.1 \mathrm{M} \text { sodium acetate (aqueous) } & \\ \begin{array}{ll} \text { (d) } 0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONH}_{4} \text { (aqueous) } & \text { (s) acidic } \\ & \text { (t) basic } \\ \hline \end{array} \end{array} \end{aligned} $$

Assertion: When aqueous solution of \(\mathrm{CH}_{3} \mathrm{COONH}_{4}\) is diluted, then its degree of hydrolysis increases. Reason: Ammonium acetate is the salt of weak acid and weak base, its degree of hydrolysis does not depend on the concentration.

\(\mathrm{K}_{\mathrm{a}_{1}} \times \mathrm{K}_{\mathrm{a}_{2}}\) for \(\mathrm{H}_{2} \mathrm{~S}=1.0 \times 10^{-21} \mathrm{M}^{2} .\) The concentration of \(\left[\mathrm{S}^{2-}\right]\) ion present in \(1 \mathrm{~L}\) of \(0.1 \mathrm{M} \mathrm{H}_{2} \mathrm{~S}\) having \(\left[\mathrm{H}^{+}\right]\) equal to \(0.1 \mathrm{M}\) is \(\mathrm{x} \times 10^{-20}\). The value of \(\mathrm{x}\) is

Acetic acid solution was \(66.6 \%\) neutralized by adding a base. If \(\mathrm{pK}_{\mathrm{a}}\) of acetic acid is \(4.7\), the \(\mathrm{pH}\) of the above solution is approximately

The sparingly soluble salt \(\mathrm{M}(\mathrm{OH})_{\mathrm{x}}\) has \(\mathrm{K}_{\mathrm{sp}}=4 \times 10^{-12}\). Its solubility is \(10^{-4} \mathrm{M}\). The value of \(\mathrm{x}\) is

A \(40 \mathrm{ml}\) sample of an aqueous solution of the methylamine at \(25^{\circ} \mathrm{C}\) is titrated with \(0.15 \mathrm{M} \mathrm{HCl}\) and theequivalence point is reached when \(40 \mathrm{ml}\) of the acid have been added. The \(\mathrm{pH}\) at the equivalence point is (Given : \(\mathrm{K}_{\mathrm{a}}\) for \(\mathrm{CH}_{3} \mathrm{NH}_{3}^{+}\)is \(\left.4 / 3 \times 10^{-11}\right)\).

\(\mathrm{K}_{\mathrm{a}}\) for \(\mathrm{HCN}\) is \(5 \times 10^{-10}\) at \(25^{\circ} \mathrm{C}\). For maintaining a constant \(\mathrm{pH}\) of 9, the vol of \(5 \mathrm{M} \mathrm{KCN}\) solution required to be added to \(10 \mathrm{ml}\) of \(2 \mathrm{M} \mathrm{HCN}\) solution is

The dissociation constants of \(\mathrm{CH}_{3} \mathrm{COOH}\) and \(\mathrm{NH}_{4} \mathrm{OH}\) in aqueous solution are almost the same. The \(\mathrm{pH}\) of a solution of \(0.01 \mathrm{~N} \mathrm{CH}_{3} \mathrm{COOH}\) is \(4.0\) at \(25^{\circ} \mathrm{C}\). The \(\mathrm{pOH}\) of \(0.01 \mathrm{~N} \mathrm{NH}_{4} \mathrm{OH}\) solutions at the same temperature will be

When \(0.01\) mole of \(\mathrm{NaOH}\) are added to a litre of buffer solution, its \(\mathrm{pH}\) changes from \(4.745\) to \(4.815\). The buffer capacity of the buffer solution is \(0.07 \mathrm{y}\). The value of \(\mathrm{y}\) is

A certain buffer solution contains equal conc. of \(X^{-}\) and \(\mathrm{HX}\). The \(\mathrm{K}_{\mathrm{a}}\) of \(\mathrm{HX}\) is \(10^{-7} .\) The \(\mathrm{pH}\) of the buffer solution is

If \(50 \mathrm{ml}\) of \(0.2 \mathrm{M} \mathrm{NaCN}\) is mixed with \(50 \mathrm{ml}\) of \(0.2\) M \(\mathrm{HCl}\), then \(\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]=\left[\mathrm{CN}^{-}\right]=\mathrm{x} \times 10^{-6}\) where \(\mathrm{x}\) is \(\left(\mathrm{K}_{\mathrm{b}}\right.\) for \(\left.\mathrm{CN}^{-}=2 \times 10^{-5}\right)\)

For the reaction \(\frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{k}\left[\mathrm{H}^{+}\right]^{\mathrm{n}}\). If \(\mathrm{pH}\) of the reaction medium changes from two to one, rate becomes 100 times that of the value at \(\mathrm{pH}=2\). The order of reaction is

Iron (II) sulphide is heated in air to form compound \(' A^{\prime}\), an oxide of sulphur. Compound 'A' is dissolved in water to give an acid. The basicity of this acid is

The \(\mathrm{K}_{\mathrm{sp}}\) of \(\mathrm{Mg}(\mathrm{OH})_{2}\) is \(1 \times 10^{-12}\), A \(0.01 \mathrm{M} \mathrm{MgCl}_{2}\) solution will precipitate at what limiting \(\mathrm{pH}\) value?

A buffer solution contains monobasic acid and its salt of concentration \(3 \mathrm{M}\) ad \(0.3 \mathrm{M}\) respectively. If \(\mathrm{pK}_{\mathrm{a}}\) of acid is 5 , the \(\mathrm{pH}\) of the solution is

The solubility of \(\mathrm{CaF}_{2}\) in water at \(25^{\circ} \mathrm{C}\) is \(1.7 \times 10^{-3} \mathrm{~g}\) per \(100 \mathrm{~cm}^{3} .\) The solubility product of \(\mathrm{CaF}_{2}\) at \(25^{\circ} \mathrm{C}\) is about \(\mathrm{x} \times 10^{-11} \mathrm{~mol} \mathrm{~L}^{-1}\). The value of \(\mathrm{x}\) is \(\ldots \ldots \ldots .\)

\(1.75 \mathrm{gm}\) of solid \(\mathrm{NaOH}\) are added to \(250 \mathrm{ml}\) of \(0.1 \mathrm{M}\) \(\mathrm{NiCl}_{2}\) solution. Calculate the approximate \(\mathrm{pH}\) of final solution. \(\left(\mathrm{K}_{\mathrm{sp}}\right.\) of \(\left.\mathrm{Ni}(\mathrm{OH})_{2}=1.6 \times 10^{-14}\right)\).

A monoprotic acid in a \(0.1 \mathrm{M}\) solution ionizes to \(0.001 \%\). If its ionization constant is \(\frac{10^{-\mathrm{x}}}{100}\), the value of \(\mathrm{x}\) is

Find the \(\mathrm{pH}\) of a \(10^{-2} \mathrm{M}\) solution of sodium salt of substituted benzoic acid if the dissociation constant of substituted benzoic acid is \(1 \times 10^{-6}\) at \(298 \mathrm{~K}\)

Calculate the \(\mathrm{pH}\) of \(10^{-8} \mathrm{M} \mathrm{HCl} \cdot(\log 11=1.0414)\)

If the solubility of \(\mathrm{RNH}_{2}(\mathrm{~g})\) in water at \(1 \mathrm{~atm}\) and \(273 \mathrm{~K}\) is \(22.4 \mathrm{~L}\) volumes of \(\mathrm{RNH}_{2}\) per unit volume of water. If \(\mathrm{pK}_{b}\) of \(\mathrm{RNH}_{2}\) is \(4 .\) Find the maximum \(\mathrm{pOH}\) that can be attained by dissolving \(\mathrm{RNH}_{2}\) in water.

Calculate \(\mathrm{pH}\) at which an acid indicator HIn with concentration \(0.1 \mathrm{M}\) changes its colour \(\left(\mathrm{K}_{\mathrm{a}}\right.\) for \(\mathrm{HIn}=\) \(\left.1 \times 10^{-5}\right)\)

When \(2 \mathrm{~L}\) of \(0.5 \mathrm{M} \mathrm{NaCl}\) is electrolysed with \(112.10 \mathrm{~F}\) of charge, the \(\mathrm{pOH}\) of resulting solution is close to (assume the concentration of \(\mathrm{Cl}^{-}\)remaining to be very small)

What is the \(\mathrm{pH}\) of a mixture obtained by mixing \(75 \mathrm{ml}\) \(\mathrm{M} / 5 \mathrm{HCl}\) and \(25 \mathrm{ml} \mathrm{M} / 5 \mathrm{NaOH}\) aqueous solution?

The dissociation constant of a substituted benzoic acid is \(1.0 \times 10^{-4}\) at \(25^{\circ} \mathrm{C}\). The \(\mathrm{pH}\) of \(0.01 \mathrm{~m}\) solution of its sodium salt is

Solubility of \(\mathrm{Ca}(\mathrm{OH})_{2}\) is \(\mathrm{S}\) mol litre \(^{-1} .\) The solubility product (Ksp) under the same condition is [2002] (a) \(4 \mathrm{~S}^{3}\) (b) \(3 \mathrm{~S}^{4}\) (c) \(4 \mathrm{~S}^{2}\) (d) \(\mathrm{S}^{3}\)

One of the following species acts as both Bronsted acid and base (a) \(\mathrm{H}_{2} \mathrm{PO}_{2}\) (b) \(\mathrm{HPO}_{3}^{2}\) (c) \(\mathrm{HPO}_{4}^{2}\) (d) all of the above