Chapter 10

The solution having higher osmotic pressure than the reference solution is called (a) Hypertonic solution (b) Isotonic solution (c) Hypotonic solution (d) Ideal solution

The osmotic coefficient of a nonelectrolyte is related to the freezing point depression by the expression, \(\phi=\Delta T_{f} /\) \(\left(m \cdot K_{e}\right) .\) The depression in freezing point of \(0.4\) molal aqueous solution of sucrose is \(0.93^{\circ} \mathrm{C}\). The osmotic coefficient is \(\left(K_{\mathrm{f}}\right.\) of water \(=1.86 \mathrm{~K}-\mathrm{kg} / \mathrm{mol}\) ) (a) \(0.8\) (b) \(1.0\) (c) \(1.25\) (d) \(0.125\)

A solution having \(54 \mathrm{~g}\) of glucose per litre has an osmotic pressure of \(4.56\) bar. If the osmotic pressure of a urea solution is \(1.52\) bar at the same temperature, what would be its concentration? (a) \(1.0 \mathrm{M}\) (b) \(0.5 \mathrm{M}\) (c) \(0.3 \mathrm{M}\) (d) \(0.1 \mathrm{M}\)

The osmolarity of \(0.2 \mathrm{M}-\mathrm{Na}_{2} \mathrm{SO}_{4}\) is (a) \(0.6 \mathrm{M}\) (b) \(0.4 \mathrm{M}\) (c) \(0.2 \mathrm{M}\) (d) \(0.8 \mathrm{M}\)

The elevation in boiling point method is used for the determination of molecular masses of (a) non-volatile and soluble solute (b) non-volatile and insoluble solute (c) volatile and soluble solute (d) volatile and insoluble solute

\(\mathrm{PtCl}_{4} 6 \mathrm{H}_{2} \mathrm{O}\) can exist as a hydrated complex. \(1.0\) molal aqueous solution has depression in freezing point of \(3.72^{\circ} \mathrm{C}\). Assume \(100 \%\) ionization and \(K_{\ell}\) of water \(=1.86^{\circ} \mathrm{C} \mathrm{mol}^{-1} \mathrm{~kg}\). The complex is (a) \(\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right)\right] \mathrm{Cl}_{4}\) (b) \(\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4} \mathrm{Cl}_{2}\right] \mathrm{Cl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) (c) \(\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3} \mathrm{Cl}_{3}\right] \mathrm{Cl} \cdot 3 \mathrm{H}_{2} \mathrm{O}\) (d) \(\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right)_{2} \mathrm{Cl}_{4}\right] \cdot 4 \mathrm{H}_{2} \mathrm{O}\)

The ebullioscopic constant of a liquid solvent is the elevation of boiling point of (a) one molar solution of non-volatile, non-electrolyte solute in it. (b) one normal solution of non-volatile, non-electrolyte solute in it. (c) one formal solution of non-volatile, non-electrolyte solute in it. (d) one molal solution of non-volatile, non-electrolyte solute in it.

A solution containing \(2.60 \mathrm{~g}\) of a nonvolatile, non-electrolyte solute in \(200 \mathrm{~g}\) of water boils at \(100.130^{\circ} \mathrm{C}\) at \(1 \mathrm{~atm}\). What is the molar mass of the solute? \(\left[K_{\mathrm{b}}\left(\mathrm{H}_{2} \mathrm{O}\right)\right.\) \(=0.52 \mathrm{~K}-\mathrm{kg} / \mathrm{mol}]\) (a) \(52.0 \mathrm{~g} \mathrm{~mol}^{-1}\) (b) \(152.0 \mathrm{~g} \mathrm{~mol}^{-1}\) (c) \(104 \mathrm{~g} \mathrm{~mol}^{-1}\) (d) \(204 \mathrm{~g} \mathrm{~mol}^{-1}\)

pH of a \(0.1\) M solution of a monobasic acid is \(2.0 .\) Its osmotic pressure at a given temperature, \(T \mathrm{~K}\) is (a) \(0.1 R T\) (b) \(0.11 R T\) (c) \(0.09 R T\) (d) \(0.01 R T\)

The molal boiling point elevation constant of water is \(0.513^{\circ} \mathrm{C} \mathrm{kg} \mathrm{mol}^{-1}\). When \(0.1\) mole of sugar is dissolved \(200 \mathrm{~g}\) of water, the solution boils under a pressure of 1 atm at (a) \(100.513^{\circ} \mathrm{C}\) (b) \(102.565^{\circ} \mathrm{C}\) (c) \(100.256^{\circ} \mathrm{C}\) (d) \(101.025^{\circ} \mathrm{C}\)

A quantity of \(3.125 \mathrm{~g}\) of a mixture of \(\mathrm{KCl}\) and \(\mathrm{NaCl}\) dissolved in \(1 \mathrm{~kg}\) of water produces a depression of \(0.186^{\circ} \mathrm{C}\) in freezing point. The molar ratio of \(\mathrm{KCl}\) to \(\mathrm{NaCl}\) in the solution (assuming complete dissociation of the salts) is \(\left(K_{f}=1.86\right.\) deg \(/\) molal \()\) (a) \(1: 3\) (b) \(2: 3\) (c) \(1: 1\) (d) \(3: 1\)

The molal boiling point elevation constant of water is \(0.513^{\circ} \mathrm{C} \mathrm{kg} \mathrm{mol}^{-1}\). When \(0.1\) mole of sugar is dissolved \(200 \mathrm{~g}\) of water, the solution boils under a pressure of 1 atm at (a) \(100.513^{\circ} \mathrm{C}\) (b) \(102.565^{\circ} \mathrm{C}\) (c) \(100.256^{\circ} \mathrm{C}\) (d) \(101.025^{\circ} \mathrm{C}\)

An aqueous solution of \(10 \%\) NaCl (consider ideal behaviour of the solution) is cooled. It will allow some (a) \(\mathrm{NaCl}\) to crystallize (b) water to freeze (c) water to solidify along with some \(\mathrm{NaCl}\) (d) precipitation of \(\mathrm{NaCl}\)

If 1 mole of a non-volatile, non-electrolyte solute in \(1000 \mathrm{~g}\) of water depresses the freezing point by \(1.86^{\circ} \mathrm{C}\), what will be the freezing point of a solution of 1 mole of the solute in \(500 \mathrm{~g}\) of water? (a) \(-0.93^{\circ} \mathrm{C}\) (b) \(-1.86^{\circ} \mathrm{C}\) (c) \(3.72^{\circ} \mathrm{C}\) (d) \(-3.72^{\circ} \mathrm{C}\)

What is the molecular mass of a nonionizing solid if \(10 \mathrm{~g}\) of this solid, when dissolved in \(100 \mathrm{~g}\) of water, forms a solution, which freezes at \(-1.24^{\circ} \mathrm{C}\) ? \(K_{\mathrm{f}}\left(\mathrm{H}_{2} \mathrm{O}\right)=1.86^{\circ} \mathrm{C} \mathrm{kg} \mathrm{mol}^{-1}\) (a) 250 (b) 150 (c) 120 (d) 75

When the depression in freezing point is carried out, the equilibrium exist between (a) liquid solvent and solid solvent (b) liquid solute and solid solvent (c) liquid solute and solid solute (d) liquid solvent and solid solute

Among the colligative properties of solution, which one is the best method for the determination of molecular masses of proteins and polymers? (a) osmotic pressure (b) lowering in vapour pressure (c) lowering in freezing point (d) elevation in boiling point

Van't Hoff's factor for a dilute solution of \(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) is (a) \(4.0\) (b) \(0.25\) (c) \(5.0\) (d) \(3.0\)

The limiting value of Van't Hoff's factor for \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) is (a) 2 (b) 3 (c) 4 (d) 5

For each of the following dilute solutions, Van't Hoff's factor is equal of 3 , except (a) \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{CaF}_{2}\) (c) \(\mathrm{K}_{3} \mathrm{PO}_{4}\) (d) \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}\)

At the same temperature, each of the following solution has the same osmotic pressure except (a) \(0.140 \mathrm{M}\) -sucrose (b) \(0.07 \mathrm{M}-\mathrm{KCl}\) (c) \(0.070 \mathrm{M}-\mathrm{Ca}\left(\mathrm{NO}_{2}\right)_{2}\) (d) \(0.140 \mathrm{M}\) -urea

Under the condition of similar temperature, which of the following solution will have minimum vapour pressure? (a) \(0.1 \mathrm{M}-\) sugar (b) \(0.1 \mathrm{M}-\mathrm{NaCl}\) (c) \(0.1 \mathrm{M}-\mathrm{BaCl}_{2}\) (d) \(0.1 \mathrm{M}-\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}\)

An aqueous solution containing \(0.25\) moles of a non-volatile but strong electrolyte solute 'X' in \(500 \mathrm{~g}\) water freezes at \(-2.79^{\circ} \mathrm{C}\). The number of ions furnished in water per formula unit of ' \(\mathrm{X}^{\prime}\) is \(\left(K_{f}=1.86\right)\) (a) 1 (b) 2 (c) 3 (d) 4

The degree of dissociation \((\alpha)\) of a weak electrolyte, \(A_{x} B_{y}\), is related to Van't Hoff factor (i) by the expression (a) \(\alpha=\frac{i-1}{x+y-1}\) (b) \(\alpha=\frac{i-1}{x+y+1}\) (c) \(\alpha=\frac{x+y-1}{i-1}\) (d) \(\alpha=\frac{x+y+1}{i-1}\)

The amino acid alanine has two isomers, \(\alpha\) -alanine and \(\beta\) -alanine. When equal masses of these two compounds are dissolved in equal mass of a solvent, the solution of \(\alpha\) -alanine freezes at relatively lower temperature. Which form, \(\alpha\) -alanine or \(\beta\) -alanine, has the larger equilibrium constant for ionization? (a) \(\alpha\) -alanine (b) \(\beta\) -alanine (c) same for both (d) unpredictable