10 gram urea di larutkan dalam 90 gram air . Jika tekanan uap air pada suhu tersebut 31 MmHg. Hitunglah tekanan uap larutan ! (Jika Mr urea = 60 g/ml)

tekanan uap larutan = 1 mmhg

wt = 10 gram (Mr = 60)
wp = 90 gram (Mr = 18)
P° = 31 mmHg
P = ............................?

nt = wt/Mr
= 10/60
= 0,17 mol
np = wp/Mr
= 90/18
= 5 mol

Xt = nt/(nt+np)
= 0,17/(0,17+5)
= 0,17/5,17
= 0,033
Xp = 1 -Xt
= 0,967

P = Xp.P°
= 0,967 x 31
= 29,98 mmHg