Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
Given: `P_A^0` = 450 mm Hg
`P_B^0` = 700 mm Hg
PTotal = 600 mm Hg
xA = ?
Applying Raoult’s law,
PA = `x_A xx P_A^0`
PB = `x_B xx P_B^0`
= `(1 - x_A)P_B^0`
PTotal = `P_A + P_B`
= `x_A xx P_A^0 + (1 - x_A)P_B^0`
= `P_B^0 + (P_A^0 - P_B^0)x_A`
Substituting the given values, we get
600 = 700 + (450 − 700)xA or 250xA = 100
or xA = `100/250` = 0.40
Thus, the composition of the liquid mixture will be
xA (mole fraction of A) = 0.40
xB (mole fraction of B) = 1 − 0.40 = 0.60
Calculation of composition in the vapour phase:
PA = `x_A xx P_A^0`
= 0.40 × 450 mm Hg
= 180 mm Hg
PB = `x_B xx P_B^0`
= 0.60 × 700 mm Hg
= 420 mm Hg
Mole fraction of A in the vapour phase = `(P_A)/(P_A + P_B)`
= ` 180/(180+420)`
= `180/600`
= 0.30
Mole fraction of B in the vapour phase = 1 − 0.30 = 0.70
APPEARS IN
संबंधित प्रश्न
In non-ideal solution, what type of deviation shows the formation of maximum boiling azeotropes?
State Raoult’s law for the solution containing volatile components
What is meant by positive deviations from Raoult's law? Give an example. What is the sign of ∆mixH for positive deviation?
An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?
The vapour pressure of water is 12.3 kPa at 300 K. Calculate vapour pressure of 1 molal solution of a non-volatile solute in it.
Some liquids on mixing form 'azeotropes'. What are 'azeotropes'?
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 |
Minimum boiling azeotrope is formed by the solution which showed
At equilibrium the rate of dissolution of a solid solute in a volatile liquid solvent is ______.
An aqueous solution of hydrochloric acid:
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.
Using Raoult’s law explain how the total vapour pressure over the solution is related to mole fraction of components in the following solutions.
\[\ce{CHCl3(l) and CH2Cl2(l)}\]
Using Raoult’s law explain how the total vapour pressure over the solution is related to mole fraction of components in the following solutions.
\[\ce{NaCl(s) and H2O(l)}\]
The correct option for the value of vapour pressure of a solution at 45°C with benzene to octane in a molar ratio of 3 : 2 is
[At 45°C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas]
If the weight of the non-volatile solute urea (NH2–CO–NH2) is to be dissolved in 100 g of water, in order to decrease the vapour-pressure of water by 25%, then the weight of the solute will be ______ g.
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.
