Chapter 5

Which of the following colligative properties can provide molar mass of proteins (or polymers or col loids) with greatest precision? (a) osmotic pressure (b) elevation of boiling point (c) depression of freezing point (d) relative lowing of vapour pressure

The beans are cooked sooner in a pressure cooker, because (a) boiling point increase with increasing pressure (b) boiling point decrease with increasing pressure (c) extra pressure of pressure cooker, softens the beans (d) internal energy is not lost while cooking in pressure cooker.

When a saturated solution of sodium chloride is heated, it (a) becomes remains saturated (b) becomes unsaturated (c) becomes supersaturated (d) achieves equilibrium state

In liquid \(\mathrm{CCl}_{4}\) which of the following has maximum solubility? (a) \(\mathrm{I}_{2}\) (b) \(\mathrm{Br}_{2}\) (c) \(\mathrm{NaCl}\) (d) \(\mathrm{Cl}_{2}^{2}\)

During osmosis, flow of water through a semipermeable membrane is (a) from both sides of semi-permeable membrane with unequal flow rates (b) from solution having lower concentration only (c) from solution having higher concentration only (d) from both sides of semi-permeable membrane with equal flow rates

Which of the following represents a metastable system? (a) an unsaturated solution (b) a dilute solution (c) a saturated solution (d) a supersaturated solution

According to Raoult's law, relative lowering of vapour pressure for a solution is equal to (a) mole fraction of the solute (b) mole fraction of a solvent (c) moles of a solute (d) moles of a solvent

When non-zero volatile solute is dissolved in a solvent, the relative lowering of vapour pressure is equal to (a) molar fraction of solute (b) molar fraction of solvent (c) concentration of the solute in grams per liter (d) concentration of the solute in gram per \(100 \mathrm{~mL}\).

The solubility of a gas in a liquid increases with (a) increase of temperature (b) amount of liquid taken (c) decrease in temperature (d) reduction of gas pressure

Which one of the statements given below concerning properties of solutions, describe a colligative effect? (a) boiling point of pure water decreases by the addition of ethanol (b) vapour pressure of pure water decreases by the addition of nitric acid (c) vapour pressure of pure benzene decreases by the addition of naphthalene (d) boiling point of pure benzene increases by the addition of toluene

The number of moles of sodium hydroxide present in \(2.5 \mathrm{~L}\) and \(0.5 \mathrm{M}\) aqueous solution will be (a) \(1.25\) (b) \(0.5\) (c) \(12.5\) (d) 5

Highest boiling point is found in (a) \(0.1 \mathrm{M}\) Sucrose (b) \(0.1 \mathrm{M} \mathrm{BaCl}_{2}\) (c) \(0.1 \mathrm{M} \mathrm{NaCl}\) (d) \(0.1 \mathrm{M} \mathrm{KCl}\)

Maximum freezing point will be for 1 molal solution of, assuming equal ionization in each case: (a) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{Cl}_{3}\) (b) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{Cl}\right] \mathrm{Cl}_{2} \cdot \mathrm{H}_{2} \mathrm{O}\) (c) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4} \mathrm{Cl}_{2}\right] \mathrm{Cl} .2 \mathrm{H}_{2} \mathrm{O}\) (d) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3} \mathrm{Cl}_{3}\right] \cdot 3 \mathrm{H}_{2} \mathrm{O}^{2}\)

The solution which has the lowest freezing point is (a) \(0.1 \mathrm{M}\) potassium nitrate (b) \(0.1 \mathrm{M}\) aluminium sulphate (c) \(0.1 \mathrm{M}\) potassium chloride (d) \(0.1 \mathrm{M}\) potassium sulphate

The vant Hoff factor 'i' accounts for (a) the extent of dissociation of solute (b) the extent of dissolution of solute (c) the degree of decomposition of solution (d) degree of solubilization of solute

The azeotropic mixture of water and ethonal boils at \(78.15^{\circ} \mathrm{C}\). When this mixture is distilled, it is possible to obtain (a) pure \(\mathrm{H}_{2} \mathrm{O}\) (b) pure \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (c) pure \(\mathrm{H}_{2} \mathrm{O}\) as well as pure \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) (d) neither \(\mathrm{H}_{2} \mathrm{O}\) nor \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) in their pure state

The solution of sugar in water contains (a) free ions (b) free atoms (c) free molecules (d) free atoms and molecules

Which of the following changes with change in temperature? (a) mole fraction (b) formality (c) \(\%(\mathrm{w} / \mathrm{W})\) (d) molality

When the solute is present in trace quantities the following expression is used (a) gram per million (b) nanogram per cent (c) microgram per cent (d) parts per million

Increasing the temperature of an aqueous solution will cause (a) decrease in molality (b) decrease in molarity (c) decrease in mole fraction (d) decrease in \% (w/w)

During depression in freezing point in a solution, the following are in equilibrium (a) liquid solvent, solid solvent (b) liquid solvent, solid solute (c) liquid solute, solid solute (d) liquid solute, solid solvent

When attraction between \(\mathrm{A}-\mathrm{B}\) is more than that of \(\mathrm{A}-\mathrm{A}\) and \(\mathrm{B}-\mathrm{B}\), the solution will show deviation from Raoult's law (a) positive (b) negative (c) no (d) cannot be predicted

People add sodium chloride to water while boiling eggs. This is to (a) decrease the boiling point of water (b) increase the boiling point of water (c) prevent breaking of eggs (d) make eggs tasty

\(\mathrm{FeCl}_{3}\) reacts with \(\mathrm{K}_{4} \mathrm{Fe}(\mathrm{CN})_{6}\) in aqueous solution to give blue colour if these two are separated by a semipermeable membrance (as shown in the figure), then due to osmosis (a) blue colour is formed towards side \(\mathrm{A}\) (b) blue colour is formed towards side B (c) blue colour is formed on both the sides side (d) no blue colouration

Which pair of the following will not form an ideal solution? (a) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Br}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{I}\) (b) \(\mathrm{H}_{2} \mathrm{O}+\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{OH}\) (c) \(\mathrm{CCl}_{4}+\mathrm{SiCl}_{4}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{14}+\mathrm{C}_{7} \mathrm{H}_{16}\)

A molal solution is one that contains one mole of a solute in (a) \(1000 \mathrm{~g}\) of the solvent (b) one litre of solvent (c) one litre of solution (d) \(22.4\) litre of the solution

A liquid is in equilibrium with its vapour at its boiling point. On the average, the molecules in the two phase have equal (a) intermolecular forces (b) potential energy (c) temperature (d) kinetic energy

The molecular weight of benzoic acid in benzene as determined by depression in freezing point method corresponds to (a) ionization of benzoic acid (b) dimerization of benzoic acid (c) trimerization of benzoic acid (d) solvation of benzoic acid

Which of the following is correct for a solution showing positive deviations from Raoult's law? (a) \(\Delta \mathrm{V}=+\mathrm{ve}, \Delta \mathrm{H}=+\mathrm{ve}\) (b) \(\Delta \mathrm{V}=-\mathrm{ve}, \Delta \mathrm{H}=+\mathrm{ve}\) (c) \(\Delta \mathrm{V}=+\mathrm{ve}, \Delta \mathrm{H}=-\mathrm{ve}\) (d) \(\Delta \mathrm{V}=-\mathrm{ve}, \Delta \mathrm{H}=-\mathrm{ve}\)

Which one of the following solution has least vapour pressure? (a) \(0.01 \mathrm{M} \mathrm{CaCl}_{2}\) (b) \(0.01 \mathrm{M}\) glucose (c) \(0.01 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\) (d) \(0.01 \mathrm{M} \mathrm{Na}_{3} \mathrm{PO}_{4}\)

A \(5 \%\) solution of sugarcane \((\) Mol \(w t=342)\) is isotonic with \(1 \%\) solution of \(X\) under similar conditions. The mol. Wt of \(X\) is: (a) \(136.2\) (b) \(68.4\) (c) \(34.2\) (d) \(171.2\)

Which of the following statement is true about ideal solutions? (a) the volume of mixing is zero (b) the enthalpy of mixing is zero (c) both \(\mathrm{A}\) and \(\mathrm{B}\) (d) none of these

The relationship between osmotic pressure at 273 \(\mathrm{K}\) when \(10 \mathrm{~g}\) glucose \(\left(\mathrm{P}_{1}\right) 10 \mathrm{~g}\) urea \(\left(\mathrm{P}_{2}\right)\) and \(10 \mathrm{~g}\) sucrose \(\left(\mathrm{P}_{3}\right)\) are dissolved in \(250 \mathrm{~mL}\) of water is (a) \(\mathrm{P}_{1}>\mathrm{P}_{2}>\mathrm{P}_{3}\) (b) \(\mathrm{P}_{3}>\mathrm{P}_{2}>\mathrm{P}_{1}\) (c) \(\mathrm{P}_{2}>\mathrm{P}_{1}>\mathrm{P}_{3}\) (d) \(\mathrm{P}_{2}>\mathrm{P}_{3}>\mathrm{P}_{1}\)

Which of the following salt will have the same volume of vant Hoff factor 'i'as that of \(\mathrm{K}_{4}[\mathrm{Fe}(\mathrm{CN})] ?\) (a) \(\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}\) (b) \(\mathrm{NaCl}\) (c) \(\mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\) (d) \(\mathrm{Na}_{2} \mathrm{SO}_{4}\)

Which of the following \(0.1 \mathrm{M}\) aqueous solutions will have the lowest freezing point? (a) \(\mathrm{K}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{NaCl}\) (c) urea (d) glucose

Camphor is used as a solvent to determine molecular weight of non-volatile solute by Rast method because for camphor (a) its molal depression constant is high (b) being very cheap (c) high melting point (d) all of these

3\. 65 grams of \(\mathrm{HCl}\) is dissolved in \(16.2\) grams of water The mole fraction of \(\mathrm{HCl}\) in the resulting solution is (a) \(0.4\) (b) \(0.3\) (c) \(0.2\) (d) \(0.1\)

By dissolving \(5 \mathrm{~g}\) substance in \(50 \mathrm{~g}\) of water, the decrease in freezing point is \(1.2^{\circ} \mathrm{C}\). The molal depression constant is \(1.85^{\circ} \mathrm{kg} \mathrm{mol}^{-1} .\) The molecular weight of substance is (a) \(105.4\) (b) \(118.2\) (c) \(137.2\) (d) \(154.2\)

\({ }^{4} \mathbf{x}\) ' grams of water is mixed in 69 grams of ethanol Mole fraction of ethanol in the resultant solution is 0.6. what is the value of ' \(x\) ' in grams? (a) 54 (b) 36 (c) 180 (d) 18

The vapours pressure of water at \(23^{\circ} \mathrm{C}\) is \(19.8 \mathrm{~mm}\). of \(\mathrm{Hg} .0 .1\) mole of glucose is dissolved in \(178.2 \mathrm{~g}\) of water. What is the vapour pressure (in \(\mathrm{mm}\) of \(\mathrm{Hg}\) ) of the resultant solution? (a) \(19.0\) (b) \(19.602\) (c) \(19.402\) (d) \(19.202\)

\(0.5 \mathrm{M}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is diluted from 1 litre to 10 litre, normaliy of the resulting solution is (a) \(1 \mathrm{~N}\) (b) \(10 \mathrm{~N}\) (c) \(11 \mathrm{~N}\) (d) \(0.1 \mathrm{~N}\)

At room temperature, the mole fraction of a solute is \(0.25\) and the vapour pressure of a solvent is \(0.80 \mathrm{~atm}\). The lowering of vapour pressure is (a) \(0.60\) (b) \(0.75\) (c) \(0.20\) (d) \(0.80\).

\(50 \mathrm{~mL}\) of \(10 \mathrm{~N} \mathrm{H}_{2} \mathrm{SO}_{4}, 25 \mathrm{~mL}\) of \(12 \mathrm{~N} \mathrm{HCl}\) and \(40 \mathrm{~mL}\) of \(5 \mathrm{~N} \mathrm{HNO}_{3}\) are mixed and the volume of the mixture is made \(1000 \mathrm{~mL}\) by adding water. The normality of resulting solution will be (a) \(9 \mathrm{~N}\) (b) \(4 \mathrm{~N}\) (c) \(1 \mathrm{~N}\) (d) \(2 \mathrm{~N}\)

The elevation in boiling point for \(13.44 \mathrm{~g}\) of \(\mathrm{CuCl}_{2}\) dissolved in \(1 \mathrm{~kg}\) of water as solvent will be \(\left(\mathrm{K}_{\mathrm{b}}=0.52 \mathrm{~kg} / \mathrm{J}\right.\), molar mass of \(\left.\mathrm{CuCl}_{2}=134.4 \mathrm{~g} / \mathrm{mol}\right)\) (a) \(0.05\) (b) \(0.10\) (c) \(0.16\) (d) \(0.20\).

The temperature at which \(10 \%\) aqueous solution of glucose will show the osmotic pressure of \(14 \mathrm{~atm}\) is (a) \(34 \mathrm{~K}\) (b) \(307.3^{\circ} \mathrm{C}\) (c) \(307.3 \mathrm{~K}\) (d) \(34^{\circ} \mathrm{C}\)

The mass of glucose that should be dissolved in \(50 \mathrm{~g}\) of water in order to produce the same lowering of vapour pressure as is produced by dissolving \(1 \mathrm{~g}\) of urea in the same quantity of water is (a) \(1 \mathrm{~g}\) (b) \(3 \mathrm{~g}\) (c) \(6 \mathrm{~g}\) (d) \(18 \mathrm{~g}\)

Osmotic pressure observed when benzoic acid is dissolved in benzene is less than that expected from theoretical considerations. This is because (a) benzoic acid is an organic solute (b) benzoic acid has higher molar mass than benzene (c) benzoic acid gets associated in benzene (d) benzoic acid gets dissociated in benzene

The rise in the boiling point of a solution containing \(1.8 \mathrm{~g}\) of glucose in \(100 \mathrm{~g}\) of solvent is \(0.1^{\circ} \mathrm{C}\). The molal elevation constant of the liquid is (a) \(1 \mathrm{~K} / \mathrm{m}\) (b) \(0.1 \mathrm{~K} / \mathrm{m}\) (c) \(0.01 \mathrm{~K} / \mathrm{m}\) (d) \(10 \mathrm{~K} / \mathrm{m}\)

At same temperature, which pair of the following solutions are isotonic solutions? (a) \(0.2 \mathrm{M} \mathrm{BaCl}_{2}\) and \(0.2 \mathrm{M}\) urea (b) \(0.1 \mathrm{M}\) urea and \(0.1 \mathrm{MNaCl}\) (c) \(0.1 \mathrm{M} \mathrm{NaCl}\) and \(0.1 \mathrm{M} \mathrm{K}_{2} \mathrm{SO}_{4}\) (d) \(0.1 \mathrm{M} \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}\) and \(0.1 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}\)

At certain temperature, a 5.12\% solution of cane sugar is isotonic with a \(0.9 \%\) solution of an unknown solute. The molar mass of solute is (a) 60 (b) \(46.17\) (c) 120 (d) 90