Question

Urea sebanyak 15 gram dilarutkan ke dalam 250 gram air jika diketahui KF air = 1,86 Celcius per M maka titik beku larutan urea tersebut adalah

Answer 1

Verified answer

Mol (n) = massa/Mr = 15/60 = 0.25 mol
molal (m) = mol/kg.pelarut = 0.25/0.25 = 1 molal
ΔTf = Kf*m = 1.86 * 1 = 1.86°C
Tf = 0 - 1.86 = -1.86°C