The equalitative sketches I, II and III given below show the variation of surface tension with molar concentration of three diferent aqueous solutions of `KCl, CH_(3)OH` and `CH_(3)(CH_(2))_(11)OSO_(3)^(-)Na^(+)` at room temperature.

The correct assignment of the sketches is

Options

A. `I:KCl" "II :CH_(3)OH" "III:CH_(3) (CH_(2))_(11)OSO_(3)^(-)Na^(+)`
B. `I:CH_(3) (CH_(2))_(11)OSO_(3)^(-)Na^(+)" "II :CH_(3)OH" "III:KCl`
C. `I:CH_(3)OH" "II :CH_(3) (CH_(2))_(11)OSO_(3)^(-)Na^(+)" "III:KCl`
D. `I:CH_(3)OH" "II: KCL " "III:CH_(3) (CH_(2))_(11)OSO_(3)^(-)Na^(+)`

Answer

D

Explanation

Surface tension of a liquid iss linked with the magnitude of the intermolecular forces present in the liquid

(I) For KCl curve, there is increase in surface tension with increase in concentration.
(II) For `CH_(3)OH` curve, surface tension decreases with the increase in concentation
(III) For `CH_(3)(CH_(2))_(11)OSO_(3)^(-)NA^(+)` curve, surface tension decreases before CMC (Crtiual micelle concentration) and then remains almost unchanged.