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प्रश्न
An azeotropic mixture of two liquids will have a boiling point lower than either of the two liquids when it ______.
पर्याय
shows a negative deviation from Raoult’s law
forms an ideal solution
shows a positive deviation from Raoult’s law
is saturated
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उत्तर
An azeotropic mixture of two liquids will have a boiling point lower than either of the two liquids when it shows a positive deviation from Raoult’s law.
Explanation:
Intermolecular forces between solute and solvent are weaker than interactions between solute and solvent when a solution deviates from Raoult’s law. The total vapour pressure of the solution is greater than the total vapour pressure of an ideal solution. Furthermore, each component’s vapour pressure is greater than expected under Raoult’s law. As a result, the azeotropic mixture of two liquids boils at a lower temperature than either liquid alone.
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संबंधित प्रश्न
Why does a solution containing non-volatile solute have higher boiling point than the pure solvent ?
A solution containing 30 g of non-volatile solute exactly in 90 g of water has a vapour pressure of 2.8 kPa at 298 K. Further, 18 g of water is then added to the solution and the new vapour pressure becomes 2.9 kPa at 298 K. Calculate:
- molar mass of the solute.
- vapour pressure of water at 298 K.
Match the following:
| (i) | Colligative property | (a) | Polysaccharide |
| (ii) | Nicol prism | (b) | Osmotic pressure |
| (iii) | Activation energy | (c) | Aldol condensation |
| (iv) | Starch | (d) | Polarimeter |
| (v) | Acetaldehyde | (e) | Arrhenius equation |
A solution containing 8.44 g of sucrose in 100 g of water has a vapour pressure 4.56 mm of Hg at 273 K. If the vapour pressure of pure water is 4.58 mm of Hg at the same temperature, calculate the molecular weight of sucrose.
Raoult’s law states that for a solution of volatile liquids the partial pressure of each component in the solution is ____________.
The boiling point of an azeotropic mixture of water and ethanol is less than that of water and ethanol. The mixture shows ____________.
Considering the formation, breaking and strength of hydrogen bond, predict which of the following mixtures will show a positive deviation from Raoult’s law?
On the basis of information given below mark the correct option.
(A) In bromoethane and chloroethane mixture intermolecular interactions of A–A and B–B type are nearly same as A–B type interactions.
(B) In ethanol and acetone mixture A–A or B–B type intermolecular interactions are stronger than A–B type interactions.
(C) In chloroform and acetone mixture A–A or B–B type intermolecular interactions are weaker than A–B type interactions.
Two liquids X and Y form an ideal solution. The mixture has a vapour pressure of 400 mm at 300 K when mixed in the molar ratio of 1 : 1 and a vapour pressure of 350 mm when mixed in the molar ratio of 1 : 2 at the same temperature. The vapour pressures of the two pure liquids X and Y respectively are ______.
A solution of a non-volatile solute in water freezes at −0.30°C. The vapour pressure of pure water at 298 K is 23.51 mm Hg and Kf for water is 1.86 degree/mol. The vapour pressure of rain solution at 298 K is ______ mm Hg.
