Question

Kedalam 10kg air di larutkan garam dapur (NaCl) sebanyak 500 gram tentukan penurunan titik beku larutan dan titik beku larutan (kf=1,86 dan mr NaCl=58,5

Answer 1

M = mol NaCl / massa air (kg)
m = (massa NaCl / Mr) / massa air
m = (500 / 58,5) / 10
m = 0,8547

Na dianggap terionisasi sempurna, maka i = 2

∆Tf = m × Kf × i
∆Tf = 0,8547 × 1,86 × 2
∆Tf = 3,18

T°f = 0°C

Tf = T°f - ∆Tf
Tf = 0 - 3,18
Tf = -3,18°C