Question

Calculate the vapour pressure of a 5% aqueous solution W/W of urea at 27°C .The vapour pressure of water at that temperature is 26.7mm of Hg.
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please answer fast.
answer to any five out of seven
complete answer. ​

Answer 1

Answer:

Mass of urea = 5 g

Mass of water = (100-5) = 95 g

No. of moles of urea =605=0.083

No. of moles of water =1895=5.278

Total number of moles =5.278+0.083

                                    =5.361

Mole fraction of solvent =5.3615.278

Ps= Mole fraction of solvent ×P0

=5.3615.278×23.5=23.14mm

Answer 2

Explanation:

Mass of urea = 5 ɢ

Mass of water = (100-5) = 95 ɢ

$No. of \ moles \ of \ urea = \frac{5}{60} = 0.083</p><p></p><p>$

$No. of \ moles \\ of water = \frac{95}{18} =5.278</p><p></p><p>$

$Total \ number \ of \ moles = 5.278 + 0.083 = 5.361</p><p></p><p>$

$Mole \ fraction \ of solvent = \frac{5.278}{5.361} </p><p></p><p>$

$Ps \= Mole fraction of solvent ×P0</p><p></p><p></p><p>$

$= \frac{5.278}{5.361 } \times 32.5 = 23.14mm$