Advertisements
Advertisements
प्रश्न
Heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components are 105.2 kPa and 46.8 kPa respectively. What will be the vapour pressure of a mixture of 26.0 g of heptane and 35 g of octane?
Advertisements
उत्तर १
Vapour pressure of heptane `(p_1^circ)` = 105.2 kPa
Vapour pressure of octane `(p_2^circ)` = 46.8 kPa
We know that
Molar mass of heptane (C7H16) = 7 × 12 + 16 × 1
= 100 g mol−1
∴ Number of moles of heptane = `26/100` mol
= 0.26 mol
Molar mass of octane (C8H18) = 8 × 12 + 18 × 1
= 114 g mol−1
∴ Number of moles of octane = `35/114` mol
= 0.31 mol
Mole fraction of heptane, x1 = `0.26/(0.26 + 0.31)`
= 0.456
And, mole fraction of octane, x2 = 1 − 0.456
= 0.544
Now, partial pressure of heptane, p1 = `x_1 p_1^circ`
= 0.456 × 105.2
= 47.97 kPa
Partial pressure of octane p2 = `x_2 p_2^circ`
= 0.544 × 46.8
= 25.46 kPa
Hence, the vapour pressure of the solution, `p_"total"` = p1 + p2
= 47.97 + 25.46
= 73.43 kPa
उत्तर २
No. of moles of heptane = `26/100` ..(Mol. mass of heptane = 100 g mol−1)
= 0.260
No. of moles of octane = `35/114` ...(Mol. mass of octane = 114 g mol−1)
= 0.307
∴ Total no. of moles in solution = 0.260 + 0.307
= 0.567
Hence, mole fraction of heptane = `0.260/0.567`
= 0.458
Mole fraction of octane = `0.307/0.567`
= 0.541
Since the solution is ideal,
`p = p_"heptane" + p_"octane"`
= (0.458 × 105.2) + (0.541 × 46.8) kpa
= 73.50 kpa
संबंधित प्रश्न
Fill in the blanks by choosing the appropriate word/words from those given in the brackets:
Ideal solutions obey ………. law and they …………. form azeotropic mixtures.
(Henry’s, aldol condensation, absence, do not, ohm, Raoult’s, increases, common ion effect, easily, three, solubility product, ohm-1, two, four, ohm-1, cm2, Cannizzaro, ohm-1 cm-1, zero, decreases, presence)
The partial pressure of nitrogen in air is 0.76 atm and its Henry’s law constant is 7.6 × 104 atm at 300 K. What is the mole fraction of nitrogen gas in the solution obtained when air is bubbled through water at 300 K?
The KH for the solution of oxygen dissolved in water is 4 × 104 atm at a given temperature. If the partial pressure of oxygen in air is 0.4 atm, the mole fraction of oxygen in solution is ______.
Two liquids X and Y on mixing gives a warm solution. The solution is ______.
The observed depression in the freezing point of water for a particular solution is 0.093°C calculate the concentration of the solution in molality. Given that molal depression constant for water is 1.86 K Kg mol-1.
For ideal solution the volume of mixing of the pure components to form the solution is ____________.
Which of the following condition is not satisfied by an ideal solution?
Which of the following is an example of a solid solution?
If two liquids A and B form minimum boiling azeotrope at some specific composition then ______.
Intermolecular forces between two benzene molecules are nearly of same strength as those between two toluene molecules. For a mixture of benzene and toluene, which of the following are not true?
(i) ∆mix H = zero
(ii) ∆mix V = zero
(iii) These will form minimum boiling azeotrope.
(iv) These will not form ideal solution.
Assertion: Molarity of a solution in liquid state changes with temperature.
Reason: The volume of a solution changes with change in temperature.
Upon increase in pressure for dissociation N2O4 into NO2, equilibrium shift towards
While titration dilute HCl solution with aqueous NaOH, which of the following will not be required?
If liquids A and B form an ideal solution, the ______.
What type of deviation from Roult’s Law is expected when phenol and aniline are mixed with each other? What change in the net volume of the mixture is expected? Graphically represent the deviation.
Suggest the most important type of intermolecular attractive interaction in the following pair.
n-hexane and n-octane
Suggest the most important type of intermolecular attractive interaction in the following pair:
I2 and CCl4
