Advertisements
Advertisements
प्रश्न
Why does a solution containing non-volatile solute have higher boiling point than the pure solvent ?
Advertisements
उत्तर
Boiling point is the temperature at which the vapour pressure of a substance becomes equal to the atmospheric pressure. According to Raoult's law, the vapour pressure of a solvent decreases in the presence of a non-volatile solute. Thus, the vapour pressure of a solution containing a non-volatile solute requires a high temperature to become equal to the atmospheric pressure. That is why the boiling point of a solution containing a non-volatile solute increases. Thus, the solution containing a non-volatile solute has a higher boiling point than a pure solvent.
संबंधित प्रश्न
What is meant by positive deviations from Raoult's law? Give an example. What is the sign of ∆mixH for positive deviation?
The vapour pressures of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if the total vapour pressure is 600 mm Hg. Also, find the composition of the vapour phase.
Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50 g of urea (NH2CONH2) is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.
What is meant by negative deviation from Raoult's law? Give an example. What is the sign of ∆mixH for negative deviation?
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.
State Raoult’s law for a solution containing volatile components. Write two characteristics of the solution which obey Raoult’s law at all concentrations.
On the basis of information given below mark the correct option.
On adding acetone to methanol some of the hydrogen bonds between methanol molecules break.
Using Raoult’s law explain how the total vapour pressure over the solution is related to mole fraction of components in the following solutions.
\[\ce{CHCl3(l) and CH2Cl2(l)}\]
The vapour pressure of pure liquid X and pure liquid Y at 25°C are 120 mm Hg and 160 mm Hg respectively. If equal moles of X and Y are mixed to form an ideal solution, calculate the vapour pressure of the solution.
An azeotropic mixture of two liquids will have a boiling point lower than either of the two liquids when it ______.
