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
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
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.
How the following conversions can be carried out?
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(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
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Show how each of the following compounds can be converted to benzoic acid.
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Describe the preparation of potassium permanganate. How does the acidifiedpermanganate solution react with
(i) iron
(II) ions
(ii) SO2 and
(iii) oxalic acid?
Write the ionic equations for the reactions.
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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)