Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50g urea `(NH_(2)CONH_(2))` is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.
Consider Raoult's law and formula for relative lowering in vapour pressure,
`(P_(A)^(0)-P_(s))/(P_(A)^(0))=(n_(B))/(n_(A))=(W_(B))/(M_(B))xx(M_(A))/(W_(A))`
Where, `(P_(A)^(0)-P_(s))/(P_(A)^(0))` is called relative lowering in vapour pressure.

Answer

`0.0168`