Solutions

A 100⁰C the vapour pressure of a solution of 6.5 g of a solute in 100 g water is 732 mm. If Kb = 0.52, the boiling point of this solution will be

• 100⁰C

• 102⁰C

• 103⁰C

• 103⁰C

Which of the following statements about the composition of the vapour over an ideal 1:1 molar mixture of benzene and toluene is correct? Assume that the temperature is constant at 25⁰C.
(Given, vapour pressure data at 25⁰C benzene = 12.8 kPa, toluene = 3.85 kPa)

• The vapour will contain a higher percentage of toluene

• The vapour will contain equal amounts of benzene and toluene

• Not enough information is given to make a prediction

• Not enough information is given to make a prediction

which is one not equal to zero for an ideal solution?

• ΔH_mix
• ΔS_mix
• ΔV_mix
• ΔV_mix

A mixture of gases contains H₂ and O₂ gases in the ratio of 1:4 (w/w).what is the molar ratio of the two gases in the mixture?

• 1:4

• 4:1

• 16:1

• 16:1

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

• X is undergoing dissociation in water

• The molecular mass of X  is greater than the molecular mass of Y.

• Molecular mass of X is less than the molecular mass of Y,

• Molecular mass of X is less than the molecular mass of Y,

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

• K₂SO₄

• K₃[Fe(CN)₆]

• Al(NO₃)₃

• Al(NO₃)₃

In Duma's method for estimation of nitrogen 0.25 g of an organic compound gave 40 ml of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300 K is 25 mm the percentage of nitrogen in the compounds is,

• 17.36

• 18.20

• 16.76

• 15.76

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

• KCl

• C₆H₁₂O₆

• Al₂(SO₄)₃

• Al₂(SO₄)₃

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be

• 5.4 g

• 10.8 g

• 54.0 g

• 54.0 g

Vapour pressure of chloroform (CHCl₃) and dichloromethane (CH₂Cl₂) at 25^oC are 200 mmHg and 41.5 mmHg 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)

• 173.9 mmHg

• 615.0 mmHg

• 347.9 mmHg

• 347.9 mmHg