Chapter 8

An aqueous solution of \(1 \mathrm{M} \mathrm{NaCl}\) and \(\mathrm{IM} \mathrm{HCl}\) is [2002] (a) not a buffer but \(\mathrm{pH}<7\) (b) not a buffer but \(\mathrm{pH}>7\) (c) a buffer with \(\mathrm{pH}<7\) (d) a buffer with \(\mathrm{pH}>7\)

\(\mathrm{pH}\) of \(0.005 \mathrm{M}\) calcium acetate \(\left(\mathrm{pKa}\right.\) of \(\mathrm{CH}_{3} \mathrm{COOH}\) \(=4.74)\) is [2002] (a) \(7.37\) (b) \(9.37\) (c) \(9.26\) (d) \(8.37\)

The solubility in water of a sparingly soluble salt \(\mathrm{AB}_{2}\) is \(1.0 \times 10^{-5} \mathrm{molL}^{-1}\). Its solubility product number will be (a) \(4 \times 10^{-15}\) (b) \(4 \times 10^{-10}\) (c) \(1 \times 10^{-15}\) (d) \(1 \times 10^{-10}\)

When rain is accompanied by a thunderstorm, the collected rain water will have a \(\mathrm{pH}\) value (a) slightly lower than that of rain water without thunderstorm (b) slightly higher than that when the thunderstorm in not there(c) uninfluenced by occurrence of thunderstorm (d) which depends on the amount of dust in air

The conjugate base of \(\mathrm{H}_{2} \mathrm{PO}_{4}^{-}\)is (a) \(\mathrm{HPO}_{4}^{2-}\) (b) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) (c) \(\mathrm{PO}_{4}^{3-}\) (d) \(\mathrm{P}_{2} \mathrm{O}_{5}\)

The molar solubility (in \(\mathrm{mol} \mathrm{L}^{-1}\) ) of a sparingly soluble salt \(\mathrm{MX}_{4}\) is 's'. The corresponding solubility product is Ksp.s is given in terms of Ksp by the relation [2004] (a) \(\mathrm{s}=(\mathrm{Ksp} / 256)^{1 / 5}\) (b) \(\mathrm{s}=(128 \mathrm{Ksp})^{1 / 4}\) (c) \(\mathrm{s}=(\mathrm{Ksp} / 128)^{1 / 4}\) (d) \(\mathrm{s}=(256 \mathrm{Ksp})^{1 / 5}\)

The conjugate base of \(\mathrm{OH}^{-}\)is [2005] (a) \(\mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{O}^{2-}\) (c) \(\mathrm{O}^{-}\) (d) \(\mathrm{O}_{2}\)

The solubility product of a salt having general formula \(\mathrm{MX}_{2}\) in water is, \(4 \times 10^{-12}\) \([2005]\) The concentration of \(\mathrm{M}^{2+}\) ions in the aqueous solution of the salt is (a) \(1.6 \times 10^{-4} \mathrm{M}\) (b) \(2.0 \times 10^{-6} \mathrm{M}\) (c) \(1.0 \times 10^{-4} \mathrm{M}\) (c) \(4.0 \times 10^{-10} \mathrm{M}\)

The molar conductivities \(\Lambda^{\circ} \mathrm{NaOA} \mathrm{c}\) and \(\Lambda^{\circ} \mathrm{HCl}\) at infinite dilution in water at \(25^{\circ} \mathrm{C}\) are \(91.0\) and \(426.2 \mathrm{~S}\) \(\mathrm{cm}^{2} / \mathrm{mol}\) respectively. To calculate \(\Lambda^{\circ} \mathrm{HOAc}\), the additional value required is (a) \(\Lambda^{\circ} \mathrm{H}_{2} \mathrm{O}\) (b) \(\Lambda^{\circ} \mathrm{KCl}\) (c) \(\Lambda^{\circ} \mathrm{NaOH}\) (d) \(\Lambda^{\circ} \mathrm{NaCl}\)

Four species are listed below [2008] (I) \(\mathrm{HCO}_{3}^{-}\) (II) \(\mathrm{H}_{3} \mathrm{O}^{+}\) (III) \(\mathrm{HSO}_{4}^{-}\) (IV) \(\mathrm{HSO}_{3} \mathrm{~F}\) Which one of the following is the correct sequence of their acid strength? (a) \(\mathrm{IV}<\mathrm{II}<\mathrm{III}<\mathrm{I}\) (b) \(\mathrm{II}<\mathrm{III}<\mathrm{I}<\mathrm{IV}\) (c) \(\mathrm{I}<\mathrm{III}<\mathrm{II}<\mathrm{IV}\) (d) III