1.

At `40^(@)C`, the vapour pressure os water is 55.3 mmHg. Calculate the vapour pressure at the same temperature over 10% aqueous solution of urea `[CO(NH_(2))_(2)]`.

Answer» Correct Answer - 53.48 mm Hg
Mass of urea in 100 g of soution = 10 = 90 g
`"Mass of water in the soltion"=100-10=90g`
`"No. of moles of urea"=((10g))/((60"g mol"^(-1)))=5.0 mol`
`"No. of moles of water" ((90g))/((18"g mol"^(-1)))=5.0 mol`
`"Mole fraction of water"=((5.0 mol))/((5.0mol)+(0.17 mol))=(5.0)/(5.17)=0.967`
`"Vapoure pressure of water over aquious solution "=P_("water")^(@)xxC_("water")=(55.3mm)xx0.967`
=53.48 mm Hg.


Discussion

No Comment Found

Related InterviewSolutions