Advertisements
Advertisements
Question
Answer the following.
How vapour pressure lowering is related to a rise in the boiling point of solution?
Solution
- At the boiling point of a liquid, its vapour pressure is equal to 1 atm.
- In order to reach boiling point, the solution and solvent must be heated to a temperature at which their respective vapour pressures attain 1 atm.
- At any given temperature the vapour pressure of a solution is lower than that of pure solvent. Hence, the vapour pressure of solution needs a higher temperature to reach 1 atm than that of needed for vapour pressure of solvent. Therefore, vapour pressure lowering causes a rise in the boiling point of a solution.
APPEARS IN
RELATED QUESTIONS
Answer the following.
Why vapour pressure of a solvent is lowered by dissolving a nonvolatile solute into it?
The following solution/solvent has maximum vapour pressure _______.
Write the expression for relative lowering of vapour pressure.
The vapour pressure of a pure liquid is 0.043 bar at a certain temperature. When a nonvolatile solute is dissolved into it, the vapour pressure of the solution is found to be 0.041 bar. What is the relative lowering of vapour pressure?
For a very dilute solution, the osmotic pressure is given by π = n2RT/V where V is the volume in L containing n2 moles of nonvolatile solute. Establish the equation for molar mass of solute.
Give two points to explain why vapour pressure of solvent is lowered by dissolving nonvolatile solute into it.
The vapour pressure of solvent decreases by 1 O mm Hg, if mole fraction of non-volatile solute is 0.2. Calculate vapour pressure of solvent.
The vapour pressure of pure solvent and solution are 120 mm Hg and 108 mm Hg respectively. The mole fraction of the solvent in the solution is ____________.
Relative lowering of vapour pressure of a solution of non-volatile solute depend only on ____________.
Which of the following is CORRECT for a solution containing non-volatile solute in it?
Which of the following is CORRECT statement?
The vapour pressure of pure benzene (molar mass 78 g/mol) at a certain temperature is 640 mm Hg. A nonvolatile solute of mass 2.315 g is added to 40 g of benzene. The vapour pressure of the solution is 600 mm Hg. The molar mass of solute is ____________.
At a constant volume, a quantity of an ideal gas has a pressure of 700 mm Hg at 300 K. At what pressure, the temperature will be halved?
According to Raoult's law, relative lowering of vapour pressure for a solution containing a nonvolatile solute is equal to ____________.
Relative lowering in vapour pressure of a solution containing non-volatile solute is the ratio of ____________.
The vapour pressure of water at 20°C is 17 mm Hg. The vapour pressure of solution containing 2.8 g urea in 50 g of water is ____________.
Relative lowering in vapour pressure depends on _______.
Identify the correct statement from the following:
38.4 g of unknown substance (molar mass 384 g mol-1) and 116 g of acetone is used to prepare a solution at 313 K. If vapour pressure of pure acetone (molar mass 58 g mol-1) is 0.842 atmosphere, what is the vapour pressure of solution?
12 g of a nonvolatile solute dissolved in 108 g of water produces the relative lowering of vapour pressure of 0.1. The molecular mass of the solute is ______.
The vapour pressure of a solvent A is 0.80 atm. When a non-volatile substance B is added to this solvent its vapour pressure drops to 0.6 atm. the mole fraction of B in the solution is ______.
Which of the following solutions will have the maximum lowering of vapour pressure at 300 K?
The vapour pressure of 100 g of water reduces from 17.53 mm to 17.22 mm when 17.10 g, of substance X is dissolved in it. Substance X can be ______.
State and explain Raoult's law for the solution of non-volatile solutes.
