Solutions

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g mL-1. The concentration of dissolved oxygen (O2) in sea water is 5.8 ppm. Then the concentration of dissolved oxygen (O2) in sea water, in terms of molality, is x 10-4 m. x = . (Nearest integer) Given: Molar mass of NaCl is 58.5 g mol-1 Molar mass of O2 is 32 g mol-1

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is: (Given : Ebullioscopic constant of water = 0.52 K kg mol-1)

1. 377.3 K
2. 379.2 K
3. 375.3 K
4. 277.3 K

A solution is made by mixing one mole of volatile liquid A with 3 moles of volatile liquid B. The vapour pressure of pure A is 200 mm Hg and that of the solution is 500 mm Hg. The vapour pressure of pure B and the least volatile component of the solution, respectively, are:

1. 1400 mm Hg, A
2. 1400 mm Hg, B
3. 600 mm Hg, A
4. 600 mm Hg, B

Which of the following graph correctly represents the plots of KH at 1 bar for gases in water versus temperature?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

When 1 g each of compounds AB and AB2 are dissolved in 15 g of water separately, they increased the boiling point of water by 2.7 K and 1.5 K respectively. The atomic mass of A (in amu) is 10-1 (Nearest integer) (Given : Molal boiling point elevation constant is 0.5 K kg mol-1)

1.24 g of AX2 (molar mass 124 g mol-1) is dissolved in 1 kg of water to form a solution with boiling point of 100.0156°C, while 25.4 g of AY2 (molar mass 250 g mol-1) in 2 kg of water constitutes a solution with a boiling point of 100.0260°C. Kb(H2O) = 0.52 kg mol-1 Which of the following is correct?

1. AX2 and AY2 (both) are completely unionised.
2. AX2 and AY2 (both) are fully ionised.
3. AX2 is completely unionised while AY2 is fully ionised.
4. AX2 is fully ionised while AY2 is completely unionised.

If A2B is 30% ionised in an aqueous solution, then the value of van't Hoff factor (i) is 10-1.

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are false
2. Statement I is true but Statement II is false
3. Both Statement I and Statement II are true
4. Statement I is false but Statement II is true

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non-volatile solute (molar mass 256 g mol-1) and the decrease in freezing point is 0.40 K?

1. 4.43 K kg mol-1
2. 3.72 K kg mol-1
3. 5.12 K kg mol-1
4. 1.86 K kg mol-1

Assume a living cell with 0.9% (w/w) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data upto first decimal place only) The cell will :

1. shrink since solution is 0.45% (w/w) as a result of association of glucose molecules (due to hydrogen bonding)
2. shrink since solution is 0.5% (w/w)
3. show no change in volume since solution is 0.9% (w/w)
4. swell up since solution is 1% (w/w)

Consider the given plots of vapour pressure (VP) vs temperature (T/K). Which amongst the following options is correct graphical representation showing Tf, depression in the freezing point of a solvent in a solution?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The observed and normal molar masses of compound MX2 are 65.6 and 164 respectively. The percent degree of ionisation of MX2 is %. (Nearest integer)

CrCl3 xNH3 can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of 0.558 C. Assuming 100% ionisation of this complex and coordination number of Cr is 6, the complex will be (Given Kf = 1.86 K kg mol-1)

1. [Cr(NH3)5Cl]Cl2
2. [Cr(NH3)4Cl2]Cl
3. [Cr(NH3)6]Cl3
4. [Cr(NH3)3Cl3]

When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ?

1. 0.2
2. 0.4
3. 0.8
4. 0.6

Consider a binary solution of two volatile liquid components 1 and 2. x1 and y1 are the mole fractions of component 1 in liquid and vapour phase, respectively. The slope and intercept of the linear plot of 1x1 vs 1y1 are given respectively as :

1. P10P20, P10-P20P20
2. P20P10, P20-P10P10
3. P20P10, P10-P20P20
4. P10P20, P20-P10P20

Arrange the following solutions in order of their increasing boiling points. (i) 10-4 M NaCl (ii) 10-4 M Urea (iii) 10-3 M NaCl (iv) 10-2 M NaCl

1. (i) < (ii) < (iii) < (iv)
2. (ii) < (i) < (iii) < (iv)
3. (iv) < (iii) < (i) < (ii)
4. (ii) < (i) (iii) < (iv)

Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is :

1. 2.79 m
2. 2 m
3. 1.79 m
4. 3 m

0.05 M CuSO4 when treated with 0.01 M K2Cr2O7 gives green colour solution of Cu2Cr2O7. The two solutions are separated as shown below : [SPM : Semi Permeable Membrane] [figure] Due to osmosis :

1. Molarity of K2Cr2O7 solution is lowered.
2. Green colour formation observed on side Y.
3. Molarity of CuSO4 solution is lowered.
4. Green colour formation observed on side X.

Molarity (M) of an aqueous solution containing x g of anhyd. CuSO4 in 500 mL solution at 32 is 2 10-1 M. Its molality will be 10-3 m. (nearest integer). [Given density of the solution = 1.25 g/mL]

The vapor pressure of pure benzene and methyl benzene at 27 C is given as 80 Torr and 24 Torr, respectively. The mole fraction of methyl benzene in vapor phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same temperature is 10-2 (nearest integer)

A solution containing 10 g of an electrolyte AB2 in 100 g of water boils at 100.52°C. The degree of ionization of the electrolyte ( ) is 10-1. (nearest integer) [Given : Molar mass of AB2 = 200 g mol-1, Kb (molal boiling point elevation const. of water) = 0.52 K kg mol-1, boiling point of water = 100°C; AB2 ionises as AB2 A2+ + 2B-]

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is (Integer answer) (Given : Molar mass in g mol-1 Ethyl alcohol : 46 water : 18)

Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is x 10-3, Value of x is . (Integer answer)

Consider the dissociation of the weak acid HX as given below HX(aq) H+(aq) + X-(aq), Ka = 1.2 10-5 [Ka : dissociation constant] The osmotic pressure of 0.03 M aqueous solution of HX at 300 K is 10-2 bar (nearest integer). [Given : R = 0.083 L bar mol-1 K-1]

When 'x' 10-2 mL methanol (molar mass = 32 g, density = 0.792 g/cm3) is added to 100 mL water (density = 1 g/cm3), the following diagram is obtained. [figure] x = (nearest integer). [Given : Molal freezing point depression constant of water at 273.15 K is 1.86 K kg mol-1]

An artificial cell is made by encapsulating 0.2 M glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a 0.05 M solution of NaCl at 300 K is 10-1 bar. (nearest integer). [Given : R = 0.083 L bar mol-1 K-1] Assume complete dissociation of NaCl

Considering acetic acid dissociates in water, its dissociation constant is 6.25 10-5. If 5 mL of acetic acid is dissolved in 1 litre water, the solution will freeze at -x 10-2 C, provided pure water freezes at 0 C. x = . (Nearest integer) Given : (Kf)water = 1.86 K kg mol-1 density of acetic acid is 1.2 g mL-1. molar mass of water = 18 g mol-1. molar mass of acetic acid = 60 g mol-1. density of water = 1 g cm-3 Acetic acid dissociates as CH3COOH CH3COO + H

2.5 g of a non-volatile, non-electrolyte is dissolved in 100 g of water at 25 . The solution showed a boiling point elevation by 2 . Assuming the solute concentration is negligible with respect to the solvent concentration, the vapor pressure of the resulting aqueous solution is mm of Hg (nearest integer) [Given : Molal boiling point elevation constant of water (Kb) = 0.52 K kg mol-1, 1 atm pressure = 760 mm of Hg, molar mass of water = 18 g mol-1]

2.7 kg of each of water and acetic acid are mixed. The freezing point of the solution will be -x C. Consider the acetic acid does not dimerise in water, nor dissociates in water. x = (nearest integer) [Given: Molar mass of water = 18 g mol-1, acetic acid = 60 g mol-1 Kf H2O : 1.86 K kg mol-1 Kf acetic acid: 3.90 K kg mol-1 freezing point: H2O = 273 K, acetic acid = 290 K]

We have three aqueous solutions of NaCl labelled as 'A', 'B' and 'C' with concentration 0.1 M, 0.01 M and 0.001 M, respectively. The value of van 't Hoff factor (i) for these solutions will be in the order :

1. iA < iC < iB
2. iA < iB < iC
3. iA > iB > iC
4. iA = iB = iC