Kraft temperature is the temperature:
- (A)below which the aqueous solution of detergents starts freezing
- (B)below which the formation of micelles takes place
- (C)above which the aqueous solution of detergents starts boiling
- (D)above which the formation of micelles takes place.✓ Correct
Answer: (D)
Solution
The Krafft temperature is the lowest temperature at which a surfactant is soluble enough for its molecules to aggregate into micelles. Below it the surfactant's solubility is too small and micelles cannot form; only above the Krafft temperature does the dissolved surfactant exceed its critical micelle concentration and assemble into micelles. It is thus the temperature above which micelle formation takes place.
JEE Main · 2020 · 06 Sep 2020 · Shift 1 · Single correct option