Chapter 5

The van't Hoff factor for \(0.1 \mathrm{M} \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}\) solution is \(2.74\). The degree of dissociation is (a) \(91.3 \%\) (b) \(87 \%\) (c) \(100 \%\) (d) \(-74 \%\)

A compound \(X\) undergoes tetramerization in a given organic solvent. The van't Hoff factor \(\dot{i}\) is (a) \(4.0\) (b) \(0.25\) (c) \(0.125\) (d) \(2.0\)

The vapour pressure at a given temperature of an ideal solution containing \(0.2 \mathrm{~mol}\) of a non-volatile solute and \(0.8 \mathrm{~mol}\) of a solvent is \(60 \mathrm{~mm}\) of \(\mathrm{Hg}\). The vapour pressure of the pure solvent at the same temperature will be (a) \(120 \mathrm{~m}\) of \(\mathrm{Hg}\) (b) \(150 \mathrm{~mm}\) of \(\mathrm{Hg}\) (c) \(60 \mathrm{~mm}\) of \(\mathrm{Hg}\) (d) \(75 \mathrm{~mm}\) of \(\mathrm{Hg}\)

The van't Hoff factors \(i\) for an electrolyte which undergoes dissociation and association in solvents are respectively (a) greater than 1 and greater than 1 (b) less than 1 and greater than 1 (c) less than 1 and less than 1 (d) greater than 1 and less than I

The amount of oxalic acid (mol. wt. 63 ) required to prepare \(500 \mathrm{ml}\) of is \(0.10 \mathrm{~N}\) solution is (a) \(0.315 \mathrm{~g}\) (b) \(3.150 \mathrm{~g}\) (c) \(6.300 \mathrm{~g}\) (d) \(63.00 \mathrm{~g}\)

The total vapour pressure of a solution of components \(A\) and \(B\) is 600 torr. The mole fraction of component \(A\) in liquid and vapour phase are \(0.70\) and \(0.35\), respectively. The vapour pressures of pure \(A\) and \(B\) are (a) 300 torr, 130 torr (b) 1300 torr, 300 torr (d) 300 torr, 300 torr (c) 300 torr, 1300 torr

Two liquids \(\mathrm{A}\) and \(\mathrm{B}\) are mixed in \(1: 4\) mole ratio to form an ideal solution. If they exert vapour pressures of \(75 \mathrm{mmHg}\) and 22 \(\mathrm{mmHg}\), respectively, the vapor pressure of liquid \(\bar{A}\) in the vapour phase would be (a) \(0.46 \mathrm{~mm} \mathrm{Hg}\) (b) \(0.66 \mathrm{~mm} \mathrm{Hg}\) (c) \(0.56 \mathrm{~mm} \mathrm{Hg}\) (c) \(0.56 \mathrm{~mm} \mathrm{Hg}\)

Among the following, the solution which shows the highest osmotic pressure is (a) \(0.05 \mathrm{M} \mathrm{NaCl}\) (b) \(0.10 \mathrm{M} \mathrm{BaCl}_{2}\) (c) \(0.05 \mathrm{M} \mathrm{FeCl}_{3}\) (d) \(0.05 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\)

Among the following, the solution which shows the highest osmotic pressure is (a) \(0.05 \mathrm{M} \mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\) (a) \(0.05 \mathrm{M} \mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\) (c) \(0.05 \mathrm{M} \mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]\) (d) \(0.04 \mathrm{M} \mathrm{FeSO}_{4} \cdot\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}\)

Which of the following aqueous solutions has the highest boiling point ? (a) \(0.1 \mathrm{M} \mathrm{KNO}_{3}\) (b) \(0.1 \mathrm{M} \mathrm{Na}_{3} \mathrm{PO}_{4}\) (c) \(0.1 \mathrm{M} \mathrm{BaCl}_{2}\) (d) \(0.1 \mathrm{M} \mathrm{K}_{2} \mathrm{SO}_{4}\)

A \(5 \%\) solution of cane sugar (mol. wt. \(=342\) ) is isotonic with a \(1 \%\) solution of a substance \(X\). the molecular weight of \(X\) is (a) \(34.2\) (b) \(171.2\) (b) \(171.2\) (d) \(136.8\)

Which one of the following aqueous solutions will exhibit highest boiling point? (a) \(0.015 \mathrm{M}\) urea (b) \(0.01 \mathrm{M} \mathrm{KNO}_{3}\) (c) \(0.01 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\) (d) \(0.015 \mathrm{M}\) glucose

Which of the following solutions will have the maximum lowering of vapour pressure at \(300 \mathrm{~K} ?\) (a) \(1 \mathrm{M} \mathrm{CaCl}_{2}\) (b) \(1 \mathrm{M} \mathrm{NaCl}\) (c) \(1 \mathrm{M}\) Phenol (d) \(1 \mathrm{M}\) Sucrose

If \(5.85 \mathrm{~g}\) of \(\mathrm{NaCl}\) is dissolved in \(90 \mathrm{~g}\) of water, the mole fraction of solute is (a) \(0.0196\) (b) \(0.01\) (c) \(0.1\) (d) \(0.2\)

Which of the following aqueous solutions will have the lowest freezing point? (a) \(0.10 \mathrm{M} \mathrm{KCl}\) (b) \(0.10 \mathrm{M} \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) (c) \(0.10 \mathrm{M} \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\) (d) \(0.10 \mathrm{M} \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{1}\)

The normality of orthophosphoric acid having purity of \(70 \%\) by wt. (specific gravity 1.54) would be (a) \(11 \mathrm{~N}\) (b) \(22 \mathrm{~N}\) (c) \(33 \mathrm{~N}\) (d) \(44 \mathrm{~N}\)

\(0.004 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\) is isotonic with \(0.01 \mathrm{M}\) glucose. The degree of dissociation of \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) is (a) \(75 \%\) (b) \(50 \%\) (c) \(25 \%\) (d) \(85 \%\)

What is the molarity of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) solution that has a density \(1.84 \mathrm{gm} / \mathrm{cc}\) at \(35^{\circ} \mathrm{C}\) and contains \(98 \% \mathrm{H}_{2} \mathrm{SO}_{4}\) by weight ? (a) \(4.18 \mathrm{M}\) (b) \(8.14 \mathrm{M}\) (c) \(18.4 \mathrm{M}\) (d) \(18 \mathrm{M}\)

What is the degree of dissociation for \(\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\) solution if van't Hoff factor \(=2.4\) ? (a) \(0.8\) (b) \(0.7\) (c) \(0.5\) (d) \(0.9\)

Twenty-five millilters of a solution of barium hydroxide on titration with a \(0.1\) molar solution of hydrochloric acid gave a titre value of \(35 \mathrm{ml}\). The molarity of barium hydroxide solution was (a) \(0.14\) (b) \(0.28\) (c) \(0.35\) (d) \(0.07\)

When mercuric iodide is added to the aqueous solution of potassium iodide, the (a) freezing point is raised (b) freezing point does not change (c) freezing point is lowered (d) boiling point does not change

How many grams of a dibasic acid (mol. wt. =200) should be present in \(100 \mathrm{ml}\) of its aqueous solution to give decinormal strength? (a) \(1 \mathrm{~g}\) (b) \(2 \mathrm{~g}\) (c) \(10 \mathrm{~g}\), (d) \(20 \mathrm{~g}\)

In a solution of \(7.8 \mathrm{~g}\) of benzene \(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) and \(46 \mathrm{~g}\) of toluene \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{3}\right)\), the mole frac of benzene is (a) \(1 / 6\) (b) \(1 / 5\) (c) \(1 / 2\) (d) \(1 / 3\)

In which mode of expression, the concentration of solution remains independent of temperature? (a) Molarity (b) Normality (c) Formality (d) Molality

How many grams of \(\mathrm{CH}_{3} \mathrm{OH}\) would have to be added to water to prepare \(150 \mathrm{ml}\) of a solution that is \(2.0 \mathrm{M} \mathrm{CH}_{3} \mathrm{OH}\) ? (a) \(9.6\) (b) \(2.4\) (c) \(9.6 \times 10^{3}\) (d) \(4.3 \times 10^{2}\)

A solution is prepared by mixing \(40 \mathrm{~g}\) of \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) and \(25.5 \mathrm{~g} \mathrm{CHCl}_{3} . \mathrm{P}^{\circ}\) for \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) is 200 \(\mathrm{nm}\) of \(\mathrm{Hg}\) and \(P^{\circ}\) for \(\mathrm{CHCl}_{3}\) is \(415 \mathrm{~nm}\) of \(\mathrm{Hg}\). Calculate the mole fraction of \(\mathrm{CHCl}_{3}\) in vapour phase. (a) \(0.28\) (b) \(0.18\) (c) \(0.38\) (d) \(0.48\)

Select the aqueous solution with the highest vapour pressure (a) \(0.2 \mathrm{M}\) Glucose (b) \(0.3 \mathrm{M} \mathrm{BaCl}_{2}\) (c) \(0.2 \mathrm{M} \mathrm{NaCl}\) (d) \(0.2 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\)

An electrolyte \(\mathrm{XY}_{2}\) is \(40 \%\) ionized. Calculate the van't Hoff factor. (a) \(1.4\) (b) \(0.4\) (c) \(1.8\) (d) \(1.6\)