Chemistry · Colligative properties of dilute solutions: a relative lowering of vapour pressure, depression of freezing point, the elevation of boiling point and osmotic pressure
Assertion Micelles are formed by surfactant molecules above the critical micella
Assertion Micelles are formed by surfactant molecules above the critical micellar concentration (CMC). Reason The conductivity of solution having surfactant molecules decreases sharply at the CMC.
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Assertion is incorrect but Reason is correct
Step-by-step solution
The assertion is correct: micelles form above CMC. The reason is also correct: conductivity increases with surfactant concentration but at CMC, the rate of increase decreases (i.e., slope decreases sharply) due to micelle formation. The reason explains the assertion because the sharp decrease in conductivity slope is a direct consequence of micelle formation, indicating that micelles begin to form at CMC.
Related MCQs
- The mass of non-volatile, non-elctrolyte solute (molar mass mol ) needed to be dissolved in octane to reduce its vapour pressure to , is…
- Solutions and are respectively glucose, and Which one of the following pairs is isotonic?…
- Which of the following solution in water will have the lowest vapour pressure?…
- A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium are classified as:…
- Which of the following is not a colloidal solution?…