Solutions · Question 25

The boiling point of 0.2 mol kg-1 solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in this case?

1. Molecular mass of X is less than the molecular mass of Y.
2. Y is undergoing dissociation in water while X undergoes no change.
3. X is undergoing dissociation in water.
4. Molecular mass of X is greater than the molecular mass of Y.

Which one of the following electrolytes has the same value of van't Hoff factor (i) as that of Al2(SO4)3 (if all are 100% ionised)?

1. Al(NO3)3
2. K4[Fe(CN)6]
3. K2SO4
4. K3[Fe(CN)6]

Which of them is not equal to zero for an ideal solution?

1. Vmix
2. P = Pobserved - PRaoult
3. Hmix
4. Smix

Of the following 0.10 m aqueous solutions, which one will exhibit the largest freezing point depression?

1. KCl
2. C6H12O6
3. Al2(SO4)3
4. K2SO4

Which condition is not satisfied by an ideal solution?

1. mixV = 0
2. mixS = 0
3. Obeyance to Raoult's Law
4. mixH = 0

Vapour pressure of chloroform (CHCl3) and dichloromethane (CH2Cl2) at 25 are 200 mm Hg and 41.5 mm Hg respectively. Vapour pressure of the solution obtained by mixing 25.5 g of CHCl3 and 40 g of CH2Cl2 at the same temperature will be (Molecular mass of CHCl3 = 119.5 u and molecular mass of CH2Cl2 = 85 u)

1. 173.9 mm Hg
2. 615.0 mm Hg
3. 90.6 mm Hg
4. 285.5 mm Hg

pA and pB are the vapour pressures of pure liquid components, A and B, respectively of an ideal binary solution. If xA represents the mole fraction of component A, the total pressure of the solution will be

1. pA + xA (pB - pA )
2. pA + xA (pA - pB )
3. pB + xA (pB - pA )
4. pB + xA (pA - pB )

A 0.1 molal aqueous solution of a weak acid is 30% ionized. If Kf for water is 1.86 C/m, the freezing point of the solution will be

1. -0.18 C
2. -0.54 C
3. -0.36 C
4. -0.24 C

200 mL of an aqueous solution of a protein contains its 1.26 g. The osmotic pressure of this solution at 300 K is found to be 2.57 10-3 bar. The molar mass of protein will be (R = 0.083 L bar mol-1 K-1)

1. 51022 g mol-1
2. 122044 g mol-1
3. 31011 g mol-1
4. 61038 g mol-1

The freezing point depression constant for water is 1.86 C m-1. If 5.00 g Na2SO4 is dissolved in 45.0 g H2O, the freezing point is changed by -3.82 C. Calculate the van't Hoff factor for Na2SO4.

1. 2.05
2. 2.63
3. 3.11
4. 0.381