tekanan uap air pada 29°c diketahui sebesar 30mm hg pada suhu sama hitunglah tekanan uap larutan urea 20% (Mr=urea=60)

Urea (aq) 20% = 20 gr, Kdr air = 80gr
Mol = massa/Mr
n Urea = 20/60 = 0,33
n Air = 80/18 = 4,44
Fraksi
Xp = np/(np + nt) = 4,44/(4,44+0,33)
Xp = 4,44/4,77
Jadi,
P = P^o * Xp
P = 30 * 4,44/4,77
P = 27,92 mmHg