The vapour pressure 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 total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.
It is given that:
PAo = 450 mm of Hg
PBo = 700 mm of Hg
ptotal = 600 mm of Hg
From Raoult's law, we have:
ptotal = PA + PB
Therefore, xB = 1 - xA
= 1 - 0.4
= 0.6
Now, PA = PAo xA
= 450 × 0.4
= 180 mm of Hg
and PB = PBo xB
= 700 × 0.6
= 420 mm of Hg
Now, in the vapour phase: Mole fraction of liquid A = PA / (PA + PB )
=180 / (180+420)
= 180/600
= 0.30
And, mole fraction of liquid B = 1 - 0.30
= 0.70
Popular Questions of Class 12th chemistry
- Q:-
Give simple chemical tests to distinguish between the following pairs of compounds.
(i) Propanal and Propanone
(ii) Acetophenone and Benzophenone
(iii) Phenol and Benzoic acid
(iv) Benzoic acid and Ethyl benzoate
(v) Pentan-2-one and Pentan-3-one
(vi) Benzaldehyde and Acetophenone
(vii) Ethanal and Propanal
- Q:- Henry's law constant for CO2 in water is 1.67 x 108Pa at 298 K. Calculate the quantity of CO2in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.">
Henry's law constant for CO2 in water is 1.67 x 108Pa at 298 K. Calculate the quantity of CO2in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.
- Q:- H2S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H2S in water at STP is 0.195 m, calculate Henry's law constant.">
H2S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H2S in water at STP is 0.195 m, calculate Henry's law constant.
- Q:-
How the following conversions can be carried out?
(i) Propene to propan-1-ol
(ii) Ethanol to but-1-yne
(iii) 1-Bromopropane to 2-bromopropane
(iv) Toluene to benzyl alcohol
(v) Benzene to 4-bromonitrobenzene
(vi) Benzyl alcohol to 2-phenylethanoic acid
(vii) Ethanol to propanenitrile
(viii) Aniline to chlorobenzene
(ix) 2-Chlorobutane to 3, 4-dimethylhexane
(x) 2-Methyl-1-propene to 2-chloro-2-methylpropane
(xi) Ethyl chloride to propanoic acid
(xii) But-1-ene to n-butyliodide
(xiii) 2-Chloropropane to 1-propanol
(xiv) Isopropyl alcohol to iodoform
(xv) Chlorobenzene to p-nitrophenol
(xvi) 2-Bromopropane to 1-bromopropane
(xvii) Chloroethane to butane
(xviii) Benzene to diphenyl
(xix) tert-Butyl bromide to isobutyl bromide
(xx) Aniline to phenylisocyanide
- Q:- A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL-1, then what shall be the molarity of the solution?">
A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL-1, then what shall be the molarity of the solution?
- Q:-
Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
- Q:-
Calculate the mass of urea (NH2CONH2) required in making 2.5 kg of 0.25 molal aqueous solution.
- Q:- A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.">
A 5% solution (by mass) of cane sugar in water has freezing point of 271 K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.
- Q:- Calculate the mass of a non-volatile solute (molar mass 40 g mol-1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.">
Calculate the mass of a non-volatile solute (molar mass 40 g mol-1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.
- Q:-
A solution is obtained by mixing 300 g of 25% solution and 400 g of 40% solution by mass. Calculate the mass percentage of the resulting solution.
Recently Viewed Questions of Class 12th chemistry
- Q:-
How would you determine the standard electrode potential of the system Mg2+ | Mg?
- Q:-
Outline the principles of refining of metals by the following methods:
(i) Zone refining
(ii) Electrolytic refining
(iii) Vapour phase refining
- Q:- You are given benzene, conc. H2SO4 and NaOH. Write the equations for the preparation of phenol using these reagents.
">You are given benzene, conc. H2SO4 and NaOH. Write the equations for the preparation of phenol using these reagents.
- Q:- Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
(i)Ethanal, Propanal, Propanone, Butanone.
(ii)Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Hint:Consider steric effect and electronic effect.
">Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions.
(i)Ethanal, Propanal, Propanone, Butanone.
(ii)Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Hint:Consider steric effect and electronic effect.
- Q:-
Write balanced equations for the following:
(i) NaCl is heated with sulphuric acid in the presence of MnO2.
(ii) Chlorine gas is passed into a solution of NaI in water.
- Q:- Calculate the depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 g of water. Ka = 1.4 x 10-3, Kf = 1.86 K kg mol-1.">
Calculate the depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 g of water. Ka = 1.4 x 10-3, Kf = 1.86 K kg mol-1.
- Q:- Arrange each set of compounds in order of increasing boiling points.
(i) Bromomethane, Bromoform, Chloromethane, Dibromomethane.
(ii) 1-Chloropropane, Isopropyl chloride, 1-Chlorobutane.
">Arrange each set of compounds in order of increasing boiling points.
(i) Bromomethane, Bromoform, Chloromethane, Dibromomethane.
(ii) 1-Chloropropane, Isopropyl chloride, 1-Chlorobutane.
- Q:-
Predict the products of electrolysis in each of the following:
(i) An aqueous solution of AgNO3 with silver electrodes.
(ii) An aqueous solution of AgNO3with platinum electrodes.
(iii) A dilute solution of H2SO4with platinum electrodes.
(iv) An aqueous solution of CuCl2 with platinum electrodes.
- Q:-
p-Dichlorobenzene has higher m.p. and lower solubility than those of o- and m-isomers. Discuss.
- Q:-
Given the standard electrode potentials,
K+/ K = - 2.93V,
Ag+/ Ag = 0.80V,
Hg2+ / Hg = 0.79V
Mg2+ / Mg = - 2.37 V,
Cr3+ / Cr = - 0.74V
Arrange these metals in their increasing order of reducing power.
6 Comment(s) on this Question
Aneesha ,what you have a doubt is another representation of the same formulað. p(total)=p(a)+p(b) which is p°(a)x(a)+p°(b)x(b) But we also know that sum of mole fractions is 1 x(b)=1-x(1) Deducing it we get the simpler form
Similar doubt as that of anisha's
What does it mean by composition ? Either it mean mole fraction or vapour pressure ?
the query of aneesha is a poor one... Ask something good baby...
It ask for composition. In your answer you give partial vp so it means composition means partial vapour pressure.
Hello. I have a small query. By using the formula P(total)=P(A)+[P(B)-P(A)]X(B), we get the value of X(B) as 0.42 and X(a) as 0.58. If done in this way, we end up multiplying 450 with 0.58 and 700 with 0.42. Why then am i ending up in the reverse order ? (the formula is given in the NCERT textbook-in terms of 1 and 2 instead of A and B)
- NCERT Chapter